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For the 2021 episode, see "Jeffy!".

Jeffy Jeffy François, (or simply referred to as Jeffy Or Jeffy Wilfred), is one of the main characters of the SML series. He is the adoptive son of Mario and Rosalina. The character was created by Logan Thirtyacre and Elaina Keyes.

He is the oldest child of Nancy and Jacques Pierre François, and the older brother of Feebee and Scooter, but since his biological father Jacques died and Nancy went to prison in "Jeffy's Parents!", he and Scooter are now the adoptive children of Mario and his wife, Rosalina.[6][7] Despite this, he still has his younger cloned brother, Scooter, who is currently wandering around outside Mario's house somewhere.

He is the secondary antagonist in Season 8, and the main antagonist in many episodes like "Jeffy Sleepwalks!", "Jeffy's Tantrum!", "Chef Pee Pee the Babysitter!", "Jeffy's Wifi Problem!", "Jeffy Plays Fortnite!", "Black Yoshi's House Arrest!", "Jeffy's Punishment!", "Hurricane Jeffy!", "Locked Out", "Jeffy the Good Boy!", "Mr. Goodman's Egg!", "Jeffy Gets Ran Over!", "Jeffy's Good Day!", and his debut episode "Mario the Babysitter!". He is also the overarching antagonist of "Jeffy's Bad Word!" and "Jeffy's Yard Sale!". Despite being an antagonist in these episodes, he is the main protagonist in some SML episodes, such as "Detective Jeffy!", "Jeffy's Parents!", "Jeffy Gets Bullied!", "Jeffy's Big Idea!" and "Jeffy's Bad Christmas". In some episodes, he is deuteragonist and tritagonist to Mario in the Mario/Jeffy videos.

Since his debut, Jeffy has proven to be very popular, most particularly with younger children. Despite his popularity, he has also caused much trouble and controversy and is overwhelmingly unpopular with many older SML fans. However, now that Jeffy has toned down his swearing and acting inappropriately, not as many fans seem to hate him as much and begin to enjoy him more. But that is not to say that people do not dislike him, as there are still some people who do.


Jeffy as a baby

Jeffy was born as Jeffy Jeffy François in a porta-potty at 7 Jeffy Street, Paris, France, on August 21, 2004, to prostitute Nancy Pierre François and painter Jacques Pierre François. They are both of French descent, but Jacques is full-blooded French. Due to not being raised properly, as well as being abused by his mother, he acts really dumb and even still wears a diaper over his pants. His mother also forced him to stick a pencil in his nose for unknown reasons. He also lost his toes through an unknown incident. This was seen in Jeffy Breaks His Leg!

At some point in his life, Jeffy moved to Florida with Feebee, his little sister, who was later killed in a bike accident possibly as Nancy took her helmet to use as an ashtray. Her death was the reason why Jeffy always wears his helmet wherever he goes.

After Nancy had enough of his antics, Jeffy was dropped off at Mario and Bowser's apartment. Jeffy lived with Mario and his family in the apartment (Causing havoc around the house, especially towards Mario), although the latter hated him before being evicted from the apartment and having to relocate to the new house.

After his wealthy father committed suicide and willed his money to Jeffy, Nancy returned to reclaim Jeffy in order to receive Jacques' money when Jeffy turns 18, but was arrested and incarcerated for child abuse, prostitution, and several other crimes. After Nancy's arrest, Mario chose to officially adopt Jeffy as his son and the two now begin to bond every day.

As of today, he is still Mario’s now adopted son and spends his days annoying and bothering the latter, playing with Junior and his friends and continuing to cause trouble and mayhem.

Since during 2020, Jeffy has began to become smart and helpful such as the time when he became a detective to help Mario getting out of jail and the time when he watch a scary movie with Mario, and Mario keep lying about the scarecrow movie while Jeffy proves he is lying. But despite this, Jeffy still loves his family.


Jeffy is somewhat different than the average teen, with a tall posture. He wears a blue bicycle helmet (with black messy hair under it), usually has a pencil shoved up his nose, has blue crossed eyes, along with a yellow T-shirt that reads "Jeffy" on it which his mother wrote so he would not forget his name. Apparently, when a different word is written on it he thinks his name is that word as seen in Jeffy’s shirt when Junior wrote “poopy butt” on it. Jeffy thought it was his actual name to the point of losing 100,000,000 dollars because of it.

He wears short dark blue jeans with a diaper (which, according to Jeffy himself, is on the outside so it doesn't get dirty), which he occasionally spanks. He wears black Adidas sneakers. His biological appearance seems to be mixed between his parents, with his blue eyes inherited from his mother and his dark brown hair inherited from his father. His face is oval-shaped with two teeth and around the nose, along with two eyelashes and a unibrow.


Starting off as a mentally-challenged baby-like kid before evolving into a slightly ditzy person who swears like a sailor, explodes in anger at any slight against him, and knowing a lot about perverted acts for someone his age, Jeffy's personality has gone through more changes than any other character. Over time, he has matured and does not annoy Mario and Rosalina as much as he used to. He barely swears any more and only acts more like a troublesome child. He is also known to be very strong, possibly one of the strongest characters in SML, as he tends to beat up bullies, hit balls really hard, and has a high pain tolerance.

He has a habit of spanking his diaper placed outside of his pants as well as soiling his pants often. When he is called a "bad boy" or in some cases a "retard", he tends to have a breakdown by throwing his head onto any surface, but calms down when he is called a "good boy" (this is no longer the case after the events of Jeffy Loses His Pencil!). However, his breakdowns can become extreme and violent, which involves curse words and being rude towards Mario and Rosalina. He also flips his desk in "First Day Of School!" because the teacher assigned a 10-page essay that was due the next day and cusses (mostly the F-word) at Jackie Chu, saying "ARE YOU F**KING HIGH?!" He often says "Why?" whenever someone tells him what to do or what not to do. He even keeps saying it whenever someone answers him. He also has a habit of calling things he likes "pee-pee".

He likes to put his "pee-pee" in various objects, especially Cheerios boxes, to the point where he somehow even impregnates one and develops romantic feelings for it.

He deeply resents Bully Bill, who picks on him and subsequently beats up all the time, but the person he hates even more is his teacher, Jackie Chu, his archrival and most hated person in the world.

He is also afraid of trivial and ridiculous things, such as animals, toilets, snow, ostriches, a flu shot, and the number 7. Based on characteristics, it is suggested that he has mental retardation. His mother delivered him to Mario because she did not love him for unknown reasons (according to Jeffy).

Despite suffering from mental retardation, Jeffy has shown traits of intelligence, but in a dumb way at times, such as in Jeffy's Homework! when he reasoned that the equation 8-4=8, since they are taking 4 out of the equation, even going on a profanity-laced rant as well as getting very smart over the years as Mario thinks he will not notice anything or remember anything but he does so he is not very dumb anymore. He is also an extremely skilled painter, a trait passed down from his father. He has also shown signs of intelligence as in Jeffy Gets Ran Over, where he remembers everything that happened to him after getting knocked out by Mario's car, as well as knowing that Mario is the one that hit him.

Jeffy has shown to be demanding, even more than the level Junior displays, as seen in Jeffy's Bedtime!, where he demands that Mario and Rosalina make his green eggs and ham, "Jeffy Gets Potty Trained!" when he demands that Rosalina give him marshmallows instead of peas, "The Hitman!", where he wanted Jello after Mario gave him green beans, he refused to eat his McDonald's Chicken Nuggets because he wasn't given 20 toys and threw them away, in "Locked Out", where he demanded chocolate cake, cried when Mario didn't give him it and locked Mario out to enjoy the cake, especially in front of Mario, and in "Jeffy Gets Help", when Jeffy yells, screams, and throws a temper tantrum because Mario said that he would not watch SpongeBob SquarePants.

Jeffy is shown to enjoy playing pranks, as seen in "Jeffy's Cellphone!", where he prank calls several places, including an employee named Josh and a prostitute, resulting Rosalina thinking Mario is cheating and beating on Mario, and in "Shrek The Babysitter!", where he locks Shrek in the bathroom with the help of Bowser Junior. Both of these videos shows that he seems to be less unintelligent, causing many fans to think that this could be a normal version of Jeffy, despite all of his intelligent moments in the series. Some people [who?] think Jeffy pretends to be retarded. When his real mother Nancy tried to claim him back, Jeffy begged Mario to let him stay and promised to be a good boy (and kept his promise by not playing the cat piano when he went back inside), indicating that he loves Mario very much. Jeffy's obsession with swearing may be from his mother and the way she acted in front of him and treated him.

Despite of all this, he is generally more on the friendly side and the bad things he do is mostly due to his unintelligence. He has his fair share of good deeds that battle the evil ones, such as being considerate of to Hansel in three episodes. He is most likely misunderstood after suffering pain from his biological mother and witnessing his twin sister and biological father's death, which might explain his outburst problems.

Although he is unintelligent, he was shown to be an adult to Mario in some episodes such as the time when he caught Mario spilling water all over his bed and Mario wanting to play with his Lego rather than eating his food. And some times he does not like to believe people like in The Halloween Heist.

Personality Traits

  • Friendly
  • Hot-headed
  • Fiery
  • Violent
  • Scatterbrained
  • Silly
  • Loud
  • Destructive
  • Reckless
  • Emotional
  • Misbehaved
  • Immature
  • Sanguine-Choleric
  • Mean
  • Somewhat Heroic
  • Dumb
  • Cranky
  • Slightly Smart
  • Obnoxious
  • Ungrateful
  • Selfish
  • Greedy
  • Whiny
  • Hardheaded
  • Inappropriate
  • Cult-Leader type


Jeffy has proven to be the most controversial character of SuperMarioLogan. Many fans complained about him by saying that he was offensive, due to him being a stereotype of mentally disabled people. Logan has responded to these claims by saying that Jeffy is meant to be funny like Chef Poo Poo, not mentally disabled.

Since Jeffy's Bad Word! and Locked Out were released, Jeffy received an immense hatred from older fans, because of him saying the word "faggot" and being an absolute jerk towards Mario. Despite this, he is also known to have a diehard fanbase, which consists of children and young teenagers, adding even more controversy. After Jeffy's Parents!, fans started to sympathize and like him even more as he had been abused by his mother, Nancy, though some fans still hate Jeffy

Jeffy's popularity grew when Jeffy The Rapper! and Jeffy's Fidget Spinner! were released, which made many young children grow fond of Jeffy and basically worship him. Later, the children constantly demanded more videos featuring him and would dislike any video that does not feature him. This caused many older fans to fuel their hatred for both Jeffy and his fanbase. In Jeffy's Fun Day!, he received a poor reception.

In December 2017, a seven-year-old boy attempted to hang himself with a noose the way Jeffy almost did in his emo form in the now-deleted Jeffy's Tantrum!. The mother of the child discovered this and reported in the news station called The Sun after he attempted to do the act. The article can be viewed here. Logan then apologized and assured that his videos are not to be imitated; despite this, YouTube started demonetizing and age-restricting all of his videos. A few months later, second-graders and third-graders watched Jeffy The Rapper! and were disciplined after mimicking him(mostly by boys).

As of late 2018 and early 2019, SML lost many of their viewers due to the fact that Jeffy became incredibly overused and popular with young children, even though his actions and language are inappropriate for their age. However, now that Jeffy doesn’t swear or act inappropriately anymore no one seems to hate him as much and begin to love him.


Magenta and White Bicycle (formerly)
Blue Bicycle with Thomas the Tank Engine (Jeffy's Coma!)


  • "Why?"
  • "UH!"
  • "ARE YOU F**KING HIGH?!?!"
  • "Hey Daddy. What doing?"
  • "You said Jeffy's a bad boy?!"
  • "Whoops."
  • Moose F*ck
  • "I don't even know."
  • "Why you do that?"
  • "My name is Jeffy, see? It says it on my shirt, Jeffy."
  • "Si Papi, Yo Quiero Mas Papi!"
  • "Bep!" or "Bep Bep Bep."
  • "I don’t have to."
  • "I don’t like it."
  • "That's so, PP!"
  • "Daddy, you're high as fuck!"
  • "PAPER!"
  • ”DADDY!!!”
  • ”I don’t want to.”
  • ”I don’t want you to.”
  • "I'm here, fuckers!"
  • "It slipped, Daddy."
  • "The new SML store is now open, so go check it out at SML!"
  • "HOW HIGH ARE YOU?!?!"
  • “I love you!”
  • "Good."
  • ”Daddy, I didn’t start anything! I’m a perfect angel~!”
  • "I wanna be a moose. All moose-f**k."
  • "DADDY- DADDY, that is not fair..."
  • "Doodle Doodle Pencil Fart."
  • "Listen here motherfucker! If you throw another goddam paper ball at me, I will fuck your shit up! I am not to be fucked with."
  • ”Well I done sh*t myself, daddy! My pants are all full of f*ck.”
  • "Booty, b*tches, and bacon."
  • "Well, toot-toot f**k sh*t!"
  • "Toot-toot pencil fart!"
  • But Daddy
  • Squeakity, Squeak Squeak Squeakity, Squeaker...
  • "That it the t*ts."
  • "Hawww give me some Pizza Daddy!!!"
  • "My daddy is the Tooth Fairy!"
  • I got a pretty cool daddy!
  • It's a pee pee Daddy!

Likes and Dislikes


  • Pooping in his pants
  • Marshmallows on pancakes
  • Playing his Cat Piano
  • Milk
  • Chocolate
  • Annoying Mario
  • Toys
  • Cheerios Box (love interest)
  • Jacques Pierre François (most likely)
  • Britknee (formerly, ex-girlfriend)
  • Prank calls
  • Bicycles
  • Perry The Platypus
  • Phineas And Ferb (most likely)
  • Pencils
  • Pokemon Cards
  • Fortnite (formerly)
  • Saying 'Si Papi, Yo Quiero Mas Papi!'
  • Magic Tricks
  • Guns
  • Cats
  • Board Games
  • Spanking his diaper
  • Nintendo Switch
  • Police
  • Foster's Home For Imaginary Friends
  • Mario
  • Saying the word "F****t" (in Jeffy's Bad Word!)
  • Making a "UH!" noise
  • The Bunny Do song (Hop Hop)
  • Rosalina
  • Throwing stuff
  • Jumping (on beds, trampolines, etc.)
  • Kicking everyone out of the house
  • Halloween
  • Chocolate cake (his favorite food)
  • Junior
  • Cody
  • Joseph
  • Toad
  • Women
  • Showing people his "pee-pee"
  • Thanksgiving
  • Lying
  • His Pooperman shirt
  • Black tar heroin
  • Cheesecake
  • Play-Doh
  • Legos
  • Fidget Spinners
  • Money
  • Indiana Jones
  • Pretending to be The Poop Monster
  • Naruto
  • Saying curse words
  • Putting barbecue sauce on chicken nuggets
  • Making animal noises
  • Giraffes
  • Santa
  • Cookies
  • Elephants
  • Dropping the F-bomb on people (especially Mario)
  • Misbehaving
  • Ketchup
  • His Nintendo Switch
  • Money
  • Giving his pets vulgar names
  • Melvin (Pee Pee Suck II/Poop Butt)
  • His Giant Inflatable Duck
  • Peeing on Mario
  • His chop saw
  • Mashed Potatoes
  • Macaroni
  • McDonalds
  • Rapping
  • Tyrone
  • Black Yoshi
  • Painting on the fence
  • SpongeBob Moves In App (In Jeffy's Tantrum!)
  • SpongeBob (his favorite show)
  • His iPad
  • His iPhone
  • Destroying green beans
  • Drawing
  • Slapping women
  • Chicken Nuggets
  • French Fries
  • Throwing cartons of milk, saying that they slipped
  • Mickey Mouse
  • Chef Pee Pee (in Chef Pee Pee The Babysitter!)
  • Roast beef
  • Pizza
  • Pizza Hut
  • Chick-Fil-A
  • Beating his meat
  • His drawing self
  • Toys R Us
  • Milkshakes
  • Coca-Cola
  • Ice Cream
  • Cheerios
  • Froot Loops
  • Lucky Charms
  • Poopy Butt (Formerly named: S**t***)
  • Messes
  • Minecraft
  • Oobi
  • Courage the Cowardly Dog
  • Watching YouTube
  • Jeffy Junior
  • Bikes
  • Piggie
  • Jeffo
  • Codo
  • Robots
  • Five Nights At Freddy's (In Robot Jeffy)
  • His Pokemon card, Politoed EX
  • Taco Bell
  • Cheerios
  • Rocket League
  • Behaving
  • Dudely Awesome
  • Gorillas
  • Gumballs
  • Oreos
  • Corn
  • Baseball
  • Twinkies
  • Cupcakes
  • Hershey's chocolate syrup
  • Carrots
  • Jimmy John's
  • String Cheese on his green beans
  • Beating up Bully Bill
  • Bumble Bee Shoes
  • Patrick
  • Driving
  • Video games
  • Chuck E Cheese's (Which he used to think was Disney World)
  • Xbox
  • Atso
  • Being expelled from his school
  • Lifesavers (candy)
  • Spider-man
  • Vanilla ice cream
  • Diet Coke
  • Broccoli
  • Peanut butter & jelly sandwiches
  • Corn (in Jeffy's Nanny!)
  • Celery
  • Salad
  • Picture of a finger
  • Presents
  • Beary (his teddy bear)
  • Cheese pizza
  • Chocolate ice cream
  • SpongeBob toys
  • Fortnite piñata
  • Fortnite toys
  • His Spider-Man mask
  • His toy Lightsaber
  • Sharks
  • Patting his diaper
  • Toilet Paper Blaster
  • Sharky
  • Bunghole
  • Gummy Worms
  • His backpack with his face on it
  • His Minecraft backpack (formerly)
  • His red Crayola toothbrush
  • His Batman action figure
  • His Mr. Potato Head toy
  • Minion playing guitar toy
  • Swimming in the toilet
  • Hippopotamuses
  • Disney World
  • Splash Mountain
  • Doing dangerous stunts
  • Destroying green beans
  • Bowling
  • Tigers (especially his pet tiger)
  • Submarine Man songs
  • The Fairly Oddparents
  • Orange Zebra
  • Being nice
  • Roast beef
  • Punch Balloons
  • A Car
  • Copying Mario
  • Hand Sanitizer
  • Green beans (in Jeffy Gets Hypnotized!)
  • Saying "Si Papi"
  • Bubble Wrap
  • Shocking Mario
  • Screaming (His Inside Voice)
  • Going Outside
  • His Earbuds of Himself
  • Selling Everything in the House
  • His PS4
  • Fall Guys
  • Spray painting the rug (In Bad Jeffy only)
  • Taking a dump in his diaper (in Baby Jeffy! and Jeffy's Scooter!)
  • Carrots
  • Cussing
  • Violence (Sometimes, when beating up Bully Bill)
  • Booger (Character)
  • Jeffy Junior II
  • Among us
  • Stretching Spider-Man
  • Stretching Hulk
  • Making sexual noises (Hawww ____ Daddy! in a high pitched voice.)
  • Mr. Buffalo
  • Super D (sometimes)
  • Blootoons (especially his show)


  • Green Beans
  • Cody saying that 2 can fit in 10 and 3 in 9 (in The Test!)
  • Bees
  • Snakes
  • Peas (sometimes)
  • Toilets
  • Violence (When not beating up Bully Bill)
  • Being called a "bad boy"
  • Spankings
  • Animals (formerly)
  • The Ticket Blaster (in Jeffy's Birthday!)
  • Turning into a green bean
  • Jeff The Killer (He calls him "Ugly Hippopotamus")
  • Ostriches
  • Lollipops
  • Pieces of gum
  • Gummy worms (formerly)
  • Getting the flu
  • Flu shots
  • Being and getting grounded
  • His shirt running away from him
  • Laughing[8]
  • Getting underpaid for his teeth
  • His helmet running away from him
  • School
  • Teachers (especially Jackie Chu)
  • Homework
  • Nazi Cheeseburger
  • Nancy (his abusive mom)
  • Evil Bathwater Bubbles
  • Taking a bath or shower
  • Snow
  • Balloons popping
  • Nazis
  • His haters
  • Luigi sucking him in Ghost Jeffy! (possibly)
  • Kidnappers
  • Dead Bodies
  • Being fat
  • People stealing his money
  • Flies
  • Bully Bill
  • Being called a retard
  • Getting Bullied
  • Bullies not following the Anti-Bullying rules
  • Losing his pencil
  • Breaking his helmet
  • The moon
  • Mario hating his rap song
  • Toad (Formerly)
  • Hiccups
  • Bears
  • Camels
  • Craig the Devil in his Nanny form
  • Lions
  • Spiders
  • Vicky Wentz (Cockerspaniel hair) (Icky Vicky) (jaggillarejdig32)[9]
  • Creepers (Minecraft)
  • Coal (which he mistakes for elephant poop in Jeffy's Bad Christmas)
  • Robber
  • Being and getting sick
  • His bicycle being taken away from him
  • Having a toy taken away from him
  • Jeffy Junior misbehaving
  • Getting detention
  • Scary Bunny
  • Taco Bomb
  • Tic Tacs (his allergy)
  • Spiders (Minecraft)
  • Having no Wi-Fi
  • Chef Pee Pee
  • Cavities
  • His helmet (In Jeffy's Switcheroo!)
  • Summer school
  • Military School
  • Being expelled (in Robot Jeffy)
  • Getting ‘raped’ (in Jeffy's Bad Word!)
  • The number 7 (in Jeffy's Biggest Fear!)
  • Pepperoni pizza
  • Green bean pizza (More so than pepperoni pizza)
  • Getting more homework
  • Vanilla ice cream
  • Diet Coke (Because it has "die" in it)
  • Broccoli (just like Junior)
  • Peanut butter & jelly sandwiches (Calls it "Peanut-poop and jelly-ass sandwiches")
  • Corn (in Jeffy's Nanny!)
  • Celery
  • Salad
  • Earthworms
  • Lifesavers (possibly)
  • His dad (sometimes)
  • Makes Bad Decisions Guy
  • Tim
  • His Minecraft backpack
  • Minecraft zombies
  • Baby arugula
  • Goodman (Possibly)
  • Boofy the Moose
  • Vacuuming
  • Candy corn
  • Atso (formerly)
  • Drugs
  • Brooklyn T. Guy (sometimes)
  • Cigarettes
  • Being evil
  • Covid
  • Mario Popping Punch Balloons with a Knife
  • Confetti (In Jeffy's Scary Movie)
  • Chocolate Cake (In Jeffy's Scary Movie!)
  • Forks
  • Balloons (In Jeffy's Scary Movie!)
  • Not Getting a car
  • The Scary Clown Movie
  • Disney world Closing
  • Mario Taking away his Diaper
  • Animal Crackers
  • Mario being immature
  • Not Getting a Car
  • Dying
  • His Party Hat (In Jeffy's 16th Birthday)
  • Being Shocked in Pain
  • Orange Zebra on the Loose
  • Mario Taking the Remote in his Helmet (In The Asteroid!)
  • Suffering from Poopy Butt's Death (In Jeffy's Bad Dog!)
  • Selling his Toys
  • Mario Snapping out of His Anger. (In Doctor Jeffy!)
  • Not being able to go Outside.
  • Not Getting his Legos.
  • Jail
  • Mario Taking His Blanket Away
  • Mario Taking his Pillow Away
  • His Xbox One (In Bad Jeffy!)
  • Fortnite (In Bad Jeffy!)
  • Cupcakes
  • Getting beaten up
  • 7
  • 6 (Possibly)
  • 67 (Possibly)
  • 69 (Possibly)
  • His Spider Man stretchy toy breaking
  • His balloon being popped
  • Craig Junior
  • Super D (Sometimes)
  • Butterball

Criminal Record

Jeffy has been known to commit crimes. He has committed more crimes than even Black Yoshi and Bowser Junior, who both regularly commit crimes. He has committed the second most crimes in SML universe, with Mr. Goodman having committed the most crimes. Being over the age of being arrested, these crimes could land him in jail.

  • Grievous Bodily Harm: Jeffy often beats up Bully Bill, normally leaving him critically injured in many casts and bandages with broken arms and black eyes. In Jeffy Goes Bowling!, he broke Rosalina's arm with a hammer while he was playing “Pin the Tail on the Donkey“ while blind. He does the same to Mario during the end of the episode. In Baby Jeffy!, he injured Brooklyn Guy with his giant rock and stack rings when he gets badly injured after fighting.
  • Fibbing: Although it's not necessarily a crime, in Jeffy's Lie!, he told a false story to the whole class about defending Godzilla after he saved 45 babies inside a hospital which was on fire when all Jeffy did was get hit in the eye with a baseball. Later it turned out to be real on the news. He refused to do it for real.
  • Kidnapping/False Imprisonment: In Jeffy's Bad Christmas, he, along with Junior and Cody captured Santa Claus and held him hostage.
  • Littering: In The Hitman!, he throws his Happy Meal out the window after realizing that he got one toy instead of twenty.
  • Animal Cruelty: In Jeffy’s Pet!, he swallows Pee Pee Suck and Melvin whole.
  • Truancy: In Jeffy's Teddy Bear!, he skips school by playing in the park with Beary. In Jeffy Skips School!, he wanted to play Fortnite all night long so he refused to do his homework and gave his clothes and his helmet to Harold as a disguise to keep him away from school. In Invisible Jeffy!, he skips school by heading to the Pensacola Beach. In Alien Jeffy!, he demands a gray alien to pretend to be himself and go to school while he plays Minecraft. In Jeffy and Junior Skip School!, he and Junior skip school by playing mini golf during a quiz. In Jeffy The Monkey!, he ordered a monkey on Amazon Primate and gave his clothes to the monkey so he could play Fall Guys and skip school. In Jeffy's Pet Dinosaur!, he and Bowser Junior escape school to find a dinosaur egg. In Pregnant Jeffy!, he escapes school early to assist Bowser Junior in babysitting their fake son, Jeffy Junior II.
  • Sexual Assault: In Invisible Jeffy!, he spanks 6 girls on their rear ends at the Pensacola Beach.
  • Filing a false report: In Jeffy's Bad Word!, he calls 911 on Mario getting him falsely arrested. After that, he lied to everybody on the news saying that Mario "raped" him when all Mario did was spank him when he wasn't listening. In Jeffy's Foster Home!, he lies to Brooklyn Guy about Mario beating him up, locking him in a coffin full of rattlesnakes, and forcing him to eat wet toilet paper when all Mario did was slap him on his hand.
  • Vandalism/Criminal Damage: In Jeffy's Mistake!, he smashes Black Yoshi's Xbox One off the balcony even though it was a dream. In Nintendo Switch, he destroys the Switch using a cutting machine. In Jeffy’s Wi-Fi Problem he shatters the dishes Mario made him wash. In Jeffy's Tantrum!, Jeffy Gets Hypnotized!, and Jeffy The Psychic!, he destroys the TV three times. He also destroyed the lamp, and a cup with a bat in Jeffy Plays Minecraft!. In Jeffy Plays Fortnite!, he rage-quits and smashes the keyboard and monitor because he was so close to getting a victory royale. He also destroyed the “Don’t Wake Daddy“ board game in Bowser Junior's Game Night 4 where he accidentally woke him up. In Jeffy's Bad Christmas, he rages over getting coal and throws the Christmas tree outside causing some of the ornaments to break and the tree to possibly break apart. Also, in Jeffy’s Scooter! he broke Scooter’s scooter (it was actually Richard’s scooter). In Jeffy and Junior Sneak Out!, he throws an inflatable shuttle into Bowser's "Mario Kart: Super Circuit" trophy, shattering the item. In Jeffy's Big Mess!, he broke many items in the living room using his bouncing ball. He also put a hole on the red couch in the game room using a knife. Plus he burned Mario's hat. In Jeffy's Punishment!, he wanted to show Bowser Junior a magic trick by pulling only the tablecloth off of the table, but he ended up destroying the dinner set. In Bad Jeffy!, he vandalized the living room carpet with spray paint. In Jeffy The Good Boy!, he destroys glass cups in the kitchen using a blue lightsaber.
  • Animal Theft/Poaching: In Jeffy's Pet Shark! he caught a shark that he named Sharky and keeps it as a pet despite Brooklyn Guy warning him that catching sharks was illegal at the time.
  • Credit Card Fraud: In Mr. Goodman's Credit Card!, he used Goodman's credit card to purchase $20,000 worth of v-bucks in Fortnite without Goodman's knowledge ($10,000 for him, and $10,000 for Bowser Junior).
  • Prank Calling: In Jeffy’s Cellphone, he prank calls places such as the police, Domino's, and Pizza Hut.
  • Driving Violations: In Jeffy's Birthday Trip!, he drives a go-kart and crashes into a metal barrier while looking at Mario. In Goodman's Son Gets a Job!, he drove Mario's car without a driver's license to McDonald's because Mario refused to get him a Happy Meal. In Jeffy's 16th Birthday!, he drives a Corvette depicting himself without a driver's license. In Jeffy's Speeding Ticket!, he drives a red Lamborghini to school without a license and gets 45 tickets. In Jeffy and Junior’s Gold Play Button!, he drives the Mario Lamborghini without a driver’s license.
  • Underage Driving: In Jeffy's Drivers License!, he takes a driving test below 16 years of age.
  • Trespassing/Breaking & Entering: In Bowser Junior's House Party!, he along with Cody and Roy Gethard sneak into Roy's neighbor's house to have a party. In Jeffy and Junior's Gold Play Button!, he and Bowser Junior sneak into Logan's house in order to steal a gold play button.
  • Not Wearing A Face Mask (COVID-19 exclusive): During the school episodes starting with Jeffy's New Friend!, he along with his classmates and Jackie Chu are in school during the COVID-19 pandemic but are not wearing face masks. In Jeffy and Junior Sneak to Disney World!, he along with Junior and Joseph go to Disney World without wearing face masks. Since July 11, 2020, face masks are mandatory in Disney World during COVID-19. In Bad Jeffy!, he goes to Target without wearing a face mask while stealing a PS4. In Roy's Cool Lessons!, he along with Joseph and Junior go to the movie theater during the COVID-19 pandemic without wearing face masks.
  • Indecent Exposure: In Jeffy's Speeding Ticket!, two out of his 45 tickets shows that he committed this crime.
  • Hit & Run: In Jeffy's Speeding Ticket!, one of his tickets shows that he ran over an old lady.
  • Armed Robbery: In Jeffy's Speeding Ticket!, he and Mario robbed a restaurant called Footlong Bangers in order to pay $10,000 to Brooklyn Guy for his 45 speeding tickets.
  • Several Traffic Violations and Speeding Tickets: In Jeffy's Speeding Ticket!, he got 45 traffic violations and speeding tickets (with 2 Indecent Exposures), so many which could've led to him being arrested.
  • Arson: In Jeffy's Big Mess!, he burned Mario's hat.
  • Attempted Arson: In Brooklyn Guy's Day Off!, he set a pot of cereal on fire which could have caused the house to burn down.
  • Harboring a Fugitive: In Jeffy's Pen Pal!, he helps Face Eater escape from prison and hide from the police
  • Genocide: In President Jeffy!, he launches nukes at every school and green bean farm in the country, even though it happened off-screen, it most likely killed hundreds of millions of civilians in the aftermath. including his parents and even himself
  • Underage Candidate: In President Jeffy!, Brooklyn Guy allowed him to run for president under the age of 35.
  • Owning An Illegal Pet: In Jeffy's Pet Tiger!, he brought a wild tiger into the house, which is an illegal pet animal to own in Florida for $2000 when Mario told him not to. In Jeffy's Pet Shark!, he caught a shark, named it Sharky, and kept it as a pet in his house.

Death Count

Jeffy's Mistake! (dream only) (Blown Up by Black Yoshi)
Jeffy Gets Stung By A Bee! (revived after being turned into a banana)
Jeffy Has Hiccups! (Mario's imagination only) (Holding Breath for too long)

Jeffy's Flu Shot! (possibly died from the flu)
Jeffy's Taco Tuesday! (Off-screen; Threw explosive tacos on the couch, killing himself, Mario, and Cody)
Jeffy's Energy Drink! (Heart attack; Revived)
Ghost Jeffy! (revived) (choked on Life Savers candy)

Jeffy’s Coma! (Brain Damaged, and Killed when the Earth Exploding by Shrek's Loudest fart.)

Among Us (Killed by Impostor; It was actually Chef Pee Pee)

President Jeffy! (Possibly died in an explosion; off-screen)

Forms and Variations

Sick Jeffy

Sick Jeffy

Sick Jeffy is Jeffy with the flu, taking way greater effect than normal would with other characters such as Mario, and having a chance of giving others the flu. His appearance also changes to rundown, tired, and overall extremely droopy. The puppet was made by a fan known as Matt'zStudioz. This version of Jeffy appeared in Jeffy's Flu Shot!.

Smart Jeffy

Smart Jeffy

Smart Jeffy is a variation of Jeffy, appearing in an episode of the same name, who is incredibly smart compared to his normal form (and everyone else), due to his pencil having impaled his brain because of a freak accident indirectly caused by Junior. However, at the end of the video, Jeffy sneezed, blowing his pencil out back down his nose, leaving a hole in his brain, and reverting him to his normal form.



A rapper variation of Jeffy that sings the songs "Why?" and "Wanna See My Pencil?."He has gotten arrested twice; the first time for shooting an elderly woman and opening up somebody's mail, the second time for slapping a girl. This version of Jeffy appeared in Jeffy The Rapper!, Jeffy The Rapper 2 and Precious's Biggest Fan!.

Green Bean Jeffy

Green Bean Jeffy

Due to the Green Bean Giant being angry at for not eating green beans, he cursed Jeffy and transformed him into a human-size green bean. The curse eventually wore off after Jeffy ate a whole plate of green beans, reverting him to his normal state. This is the primary reason why Jeffy no longer complains about green beans until Jeffy's Cat Piano Problem!. This variant appeared in Jeffy And The Beanstalk!.

Redneck Jeffy


Redneck Jeffy is a variation of Jeffy with a Redneck's brain in his skull. After Jeffy sneezed his brain out, the doctor accidentally dropped his brain in his recycled brain bin, and they had to spend 8 hours picking out random brains, one of the brains was the Redneck's brain. He wears a Sombrero, rattles a Maraca, and talks in a Southern accent. This version of Jeffy appeared in Jeffy's Brain!. He also sounds a lot like Woody.

Drawing/Play-Doh Jeffy

For More information check out Drawing Jeffy

Drawing Jeffy is a clone of Jeffy that he accidentally created by saying "Doodle doodle pencil fart!". Junior traps him into a piece of paper, and he is not seen until Jeffy Sneaks Out!, where Jeffy accidentally revives him with Play-Doh. He is shot and killed by Mario. This is the variation of Jeffy that has had the most appearances. The puppet for this version was made by a fan. he also killed Simmons, Brooklyn T. Guy's best friend but threatened to kill Mario and Rosalina which makes him a villain.

Jeffy App Salesman


Although not a form or variation of Jeffy, it is an identical person, looking and talking exactly like him, aside from wearing Marx glasses. This version of Jeffy appeared in Jeffy's Tantrum!.

Angry Jeffy

Angry Jeffy

Jeffy turns way more angry than usual after eating tic-tacs. He gets so mad that he even shouts at Junior, who is one of his best friends. It looks like the normal Jeffy, but with big slanted eyebrows. He appears in Jeffy Gets Help!.

Depressed Jeffy

Depressed Jeffy

Jeffy's face gets really messed up, similar to Drawing Jeffy. However, he is black and white and is suicidal. This form's Jeffy isn't energetic like his normal self. This happened after eating tic-tacs. The puppet for this version of Jeffy was made by a fan. He appears in Jeffy Gets Help!. He reappears in a Chilly vlog, where he went to the airport to fly to South Florida.

Wig Jeffy

Wig Jeffy

Jeffy has lots of overgrown "hair" that needs to be cut. After Mario sees him, he goes to call a Hair Cutter to cut Jeffy's "hair". Before he cuts it, Jeffy shakes his head, revealing that it is actually a wig.

Taco Jeffy

Jeffy dresses up in his taco suit. His appearance is a standard hard-shelled taco with meat, lettuce, and cheese. Jeffy asks Mario to buy him tacos from Taco Bell because it's Taco Tuesday. Jeffy's body can still be seen behind the taco, with Jeffy's head sticking through the front of the suit.


For more information, check out Scooter.


Scooter is a clone of Jeffy. He was made by Cody's Crazy Cool cloning machine (or C-C-C-Cloning machine). They had a short relationship with each other as he was shot in the face with a Nerf gun by Bowser Junior only minutes after he was made. He likes to say "Hey fat boy, wanna fight?".

However, after an absence for two years, Scooter returned in Jeffy and Junior Skip School!

Baby Jeffy


In the episode, Jeffy drank too much youth juice, turning him into a baby. Baby Jeffy starts Fighting Against Brooklyn T Guy and Beats him up. This is also the only form of Jeffy that has toes.

Old Jeffy

Old Jeffy

In the episode Baby Jeffy!, Jeffy drank too much old juice, turning him into old Jeffy. Old Jeffy has gray hair instead of brown hair. Although he acts like normal Jeffy, he acts slower than normal. He shares a similar appearance and voice with Harold Wilfred.

Zombie Jeffy

In the episode Zombie Jeffy!, Mario presumably kills Jeffy after shooting a green bean down his throat causing him to choke. While Rosalina and Mario are mourning the loss of Jeffy, suddenly he shows up again and Mario, Rosalina, and Brooklyn T. Guy try taking care of him and Brooklyn T. Guy talks to him in Zombie language. They get Mario to stick his head in a porta potty for 10 minutes, and afterwards they reveal that everything was a prank, and Rosalina put makeup on Jeffy, and Brooklyn T. Guy amputated his arm, which they had to get sewed back on later.



Before Season 9, Mario and Jeffy formerly had bad blood against each other. Mario also hates his stupidity and how he can annoying sometimes. Although he is protective, such as when he lost Jeffy where he eats, and when Jeffy had a gun, he was looking and telling Jeffy to put the gun down (even though he should've been happy because he wouldn't have to deal with Jeffy anymore). He also shot Jeffy with a Nerf gun in Bowser Junior's Nerf War! In Where's Jeffy?, Mario abandoned Jeffy at the park. However, when Jeffy turned smart, Mario liked him very much and told him that he was proud that he was his son, and was sad when he turned back to normal due to him losing the international world smart person contest.

Jeffy with Mario

However. in the episode Jeffy's Parents!, it showed Mario's good side on Jeffy and officially adopts him. He missed Jeffy when his mother came to take him home. Mario called the cops on her and rooked her to Jail for Child Abuse, Prostitution . After learning Jeffy’s tragedy and how his former father was a millionaire and killed himself and give all his money to him, Mario now officially adopts him and they are now officially father and son.

Despite their differences, Mario and Jeffy still love each other deep down, and can't live without each other, developing a relationship similar to Bowser Junior and Chef Pee Pee or a relationship similar to Bowser Junior and Bowser.

Status: Neutral (Friends on Mario's side)

Bowser Junior

Jeffy with Bowser Junior

Considering how widely popular and relevant both characters are, Jeffy and Bowser Junior are very good friends. They enjoy hanging out with each other and make a good team.

When Jeffy and Junior met for the first time in Bowser Junior's Game Night 3, Junior called Jeffy awesome for surviving a game of Russian Roulette. Jeffy was indirectly also the reason for Mario and Junior permanently recognizing each other starting from that episode, and he also seems to like Junior. As of recently, both Junior and Jeffy seem to get along more, as shown in Shrek The Babysitter! and Smart Jeffy. Junior even caused the main plot elements of Smart Jeffy and Jeffy Loses His Teeth!, wherein he made a jump from a trampoline and hit a table in the former, and accidentally knocked one of Jeffy's teeth out with a T-ball bat in the latter. However, Jeffy and Junior have had major conflicts between each other in the past, such as Junior being responsible for the death of Jeffy's children Puss Hole and Puss Hole 2 in Jeffy's Kids!, a deleted video. Despite this, they generally seem to be on a good term regardless. After Jeffy and Junior skip school, where Jeffy agreed with junior to skip school to go mini-golfing. He and Junior are now best friends to a point where junior plays with him more than Cody and Joseph. In Jeffy and Junior's Big Heist, Jeffy helped Junior retrieve Charleyyy’s underwear and getting him to sign it as they both disguised as people from corporate to make him sign it. He and Junior are now best friends.

Status: Best Friends


Cody and Jeffy are good friends. Although sometimes Jeffy can get on Cody's nerves, Cody doesn't mind this. Cody finds Jeffy extremely stupid as seen in The Test! when he fails to teach Jeffy proper math. Along with Bowser Junior. Cody sometimes finds opportunities to rape Jeffy, it is unknown if Cody was able to rape Jeffy in The Remote! as Cody sometimes find's Jeffy attractive.

Status: Neutral (enemies on some occasions)


Debuting in Jeffy's Parents!, Nancy is shown to be very abusive towards her son, to a much higher extent than Mario was. Nancy acted as she cared about him when people were around, but when they were alone she would always beat him. Nancy eventually got arrested and Jeffy ended up getting adopted by Mario.

Status: Arch-enemies


Jeffy and Rosalina seem to get along well, going to where Rosalina copies Jeffy a lot. Jeffy usually calls Rosalina "Mommy" just like how he calls Mario "Daddy". Rosalina acts like a deep motherly figure to Jeffy, to the point of sometimes caring more about Jeffy, and calling Mario out whenever he abuses Jeffy, even breaking up with Mario when he heartlessly let Jeffy go with Nancy. She most likely does this as she wants to be the mother Jeffy was “supposed“ to have as Nancy abused him which makes Rosalina mad as she absolutely hates to a point at even trying to break up with Mario as he tried to give Jeffy back to Nancy. He will yell at her occasionally if he does not get his way, but despite this, He mostly loves her as a mother. Rosalina is more loving and caring towards Jeffy to the point where she acts as a motherly figure and calling Mario off whenever he gets angry at Jeffy.

Status: Neutral (Friends on Rosalina's side)

Jacques Pierre François

Not much is known about Jeffy's relationship with his dad, world-renowned French painter Jacques Pierre François, who had passed away after committing suicide in pursuit of his art. Due to the fact that Jeffy's "IF LOST" paper contains Jacques's name and address information, this could imply that Jacques used to care about Jeffy. Jeffy has also claimed that he learned basic French from his father.

Status: Friends


In Jeffy's Sister!, it was revealed that Jeffy has a sister named Feebee. Jeffy and Feebee are very similar in character, with nearly exactly the same traits. They can even communicate with each other through diaper patting. However, it was revealed in Jeffy's Sister Returns!, that Jeffy's sister Feebee was killed when she got hit by a truck while riding a bike and died back in 2015.

Status: Siblings

Brooklyn T. Guy

Most of the time, Brooklyn T. Guy doesn't seem to mind and cares about Jeffy, as shown in episodes such as Mario The Babysitter!, Jeffy's Bad Word!, Jeffy Goes To The Zoo! and Locked Out. But he still likes him as a friend. However, in the third episode of Who Wants To Be A Millionaire?, Brooklyn Guy is shown to get annoyed with Jeffy's behavior and is sometimes Jeffy’s Arch-Rival

Status: Friends (Enemies on occasions)

Chef Pee Pee

Jeffy seems to like Chef Pee Pee, but Chef Pee Pee, like Mario, does not seem to have the patience for Jeffy. For instance, he got annoyed with when Mario and he were trying to get to eat his green beans. Chef Pee Pee also seemed upset when Jeffy ruined the pencil cake Chef Pee Pee made for him. When Chef Pee Pee babysat Jeffy, he was so annoyed by Jeffy's shenanigans to point that he was would've killed Jeffy if Mario hadn't showed up in time.

Status: Neutral (Friends on Chef Pee Pee’s side)

Black Yoshi

Jeffy doesn't seem to have much of a relationship with Black Yoshi. The two have only unofficially met in one video Jeffy's Mistake! but the events in that video are a dream. However, Black Yoshi and Jeffy have mentioned each other many times in future episodes, like Jeffy's Piggy Bank! and they seem to rather have more of a positive relationship rather than a negative one.

Status: Neutral


Jeffy and Shrek don't seem to have a good relationship because Jeffy locked him in the bathroom and ate his cheesecake along with Bowser Junior so Shrek locked both of them in the bathroom with the toilet clogged.

Status: Enemies


Jeffy and Toad seem to be rivals when it comes to the rap game, however outside of rapping, for the most part they seem to be on good terms, even if they don't have much interaction outside of rapping.

Status: Neutral (Enemies while rapping)

Bully Bill

Jeffy is a frequent target for Bully Bill. However, Jeffy does not take it lying down, and turns Bully Bill's bullying on him with extreme physical violence. Despite the number of beatings he has taken, Bully Bill never learns his lesson because he is an idiot.

Status: Enemies


Jeffy and Bowser don't seem to have a good relationship due to how Bowser accidentally gave Jeffy the flu by coughing in his mouth in Jeffy's Flu Shot!, how Bowser acted harshly towards Jeffy in The Competition! and how Bowser mistook the shock collar remote for the TV remote and repeatedly used it, shocking Jeffy and indirectly framing Mario in Jeffy's Punishment!, as well as how Jeffy was paid by Mario to break Bowser's trophy in Jeffy and Junior Sneak Out!. Jeffy, however, did congratulate Bowser when he won Charleyyy's underwear in Jeffy and Junior's Big Heist!, but other after that, for the most part they seem to be on good terms, even if they don't have much interaction with each other.

Status: Neutral (Enemies on rare occasions)

Jackie Chu

When they first met in the First Day Of School!, Jackie Chu, at first, never like him because of his bad behavior and Jeffy hates him because the latter yells at him, sents him to detention, and makes fun of him by calling him a b**ch. Although the two hated each other all the time, but on extremely rare occasions, they kinda have a good relationship with each other, two examples that have the two being on good terms is in The Baby Project! where Jackie Chu gives Jeffy and Junior an A for killing the baby and in The Science Fair! where he gives Jeffy an A+ for melting crayons on his rainbow popcorn project.

Status: Enemies (Friends on extremely rare occasions)

Abilities / Super Powers

Bringing Drawings To Life

Jeffy has a spell called Doodle Doodle _____ Fart. One example was Drawing Jeffy! where Jeffy said "Doodle Doodle Pencil Fart". Jeffy can only do this with the pencil in his nose.


Jeffy was able to predict the future in Jeffy The Psychic!. One example was when he knew that Brooklyn T. Guy charged Mario 10 grand for wasting his time.

Magic / Flight

In Fat Jeffy, Brooklyn T. Guy proved to Mario and Jeffy that they could do anything because they were toys. And when they knew that, they flew to the kitchen room. This power was also the main subject and Jeffy's Magical Pencil!. He had the ability to turn people into things/animals/creatures only for the pencil to choose. That was proven when Jeffy tried to fix Mario but accidentally turned him into a Minecraft Zombie due to the pencil choosing so. Everything was fixed when the glitter was washed off Jeffy's pencil. This is proof that the glitter on Jeffy's Pencil gave it the power to turn people into other things/people.

High Strength

Jeffy is possibly one of the strongest characters in the SuperMarioLogan franchise, so is Bully Bill. But that does not stop Jeffy from handing Bully Bill's ass to him, and Beat up Brooklyn T. Guy even as a Baby.

Sleuth Skills

In Detective Jeffy, he is shown to have skills as a detective as he is able to find clues better than the police.


  • The Jeffy puppet was made by Evelina (Eva Gronowitz) from Beacon Art Studios. It can be found on her Etsy website and costs $513.00 USD.
  • Jeffy has had five birthdays since he was taken in by Mario, making him 16 due to his age being revealed in Jeffy's Parents! when Brooklyn T. Guy read the note with Jeffy's information.
  • Logan said in multiple videos that Jeffy was originally going to a side character, but he turned out to be so big and popular by fans and young children, he became a permanent character in the SML franchise.
    • Many fans have speculated that Jeffy was the main reason for older characters such as Tony, Woody, and Shrek to not appear in more recent SML videos. However, Logan revealed in a Livestream that Jeffy was the replacement for Tony, since Lance couldn't do Tony's voice as well as he used to, which upset many older fans.
  • Lance Thirtyacre's Meet the Cast video reveals a few behind-the-scenes aspects about Jeffy.
    • Jeffy was originally going to be named Doofy; however, to avoid confusion with Doofy The Dragon, they ended up with naming him Jeffy.
    • He was originally going to be voiced by Chris but due to him voicing Brooklyn T. Guy he couldn't voice Jeffy since it would be hard for him to voice two characters in one scene.
    • Jeffy was actually supposed to have a red helmet, but it never happened but in a video his helmet was red for a few minutes.
    • Jeffy’s eyes were originally far apart, but due to him looking like a snake they brought his eyes closer.
    • When the SML crew first got the Jeffy puppet, he did not have a diaper, a pencil in his nose and didn't have the name Jeffy written on his shirt.
  • Lance's Character Q&A video reveals a few things about Jeffy.
    • His favorite foods are carrots and chocolate cake. He also likes pancakes with marshmallows.[10]
    • Jeffy prefers cats over dogs. This is evident with how he frequently plays with his Cat Piano.
    • Jeffy says he never laughed, but this is untrue, since in First Day Of School! you can see him laughing with Junior when he put on his name card "Poopy Butt" and in Jeffy's Trap!, he is seen laughing.
      • It is possible Lance did not remember those episodes or because of how rare it is for Jeffy to actually laugh, it could be why he answered that.
    • The reason why he spanks his diaper is that it "feels good on his pee pee".
    • His favorite color is a carrot (which possibly means it's Orange.)
  • According to Logan, the main Jeffy puppet's pants are sewed on. Any time he is seen naked or without his pants, he is shown either from the waist up or a stunt double is used.
  • Jeffy received an immense hatred from most fans in 2016, namely after Jeffy’s Bad Word!, however, after Jeffy’s Parents!, most fans stopped hating him and started to show him love, though some fans, namely older ones, continue to hate him to this day.
  • Logan has many stunt doubles for Jeffy along with any other character
    • He reused four Jeffy stunt doubles as new characters. Three were reused into Jeffy's Emotions (Joy Jeffy, Anger Jeffy, and Sad Jeffy) while a fourth was reused into Face Eater.
    • Logan also reused parts of another Jeffy stunt double with parts of a Bowser Junior plush into Jeffy Junior.
  • Logan has confirmed in a Chilly vlog that he is going to take a break from using Jeffy, as he has caused his channel problems since his debut in Mario The Babysitter!; however, Jeffy will return sometime soon again.
  • It's revealed in Jeffy Gets Help! that Jeffy is allergic to Tic Tacs.
  • Jeffy is one of the strongest characters in the series since he has beaten up Brooklyn Guy, Bully Bill and Santa Claus.
  • Jeffy is similar to Leland from Oh Shiitake Mushrooms (AKA: Kid Temper Tantrum)
  • Jeffy likes mashed potatoes.
  • Part of Jeffy's full name, Jeffy Jeffy, may be a reference to Mario's full name, Mario Mario.
    • Though, Jeffy's last name is confirmed to be François like his biological father.
  • It has not been confirmed if Jeffy suffers from a mentally disability and/or retardation.
    • He is, however, implied to have Down syndrome, as stated in Bowser Junior Kinda Goes Camping!, when he says "I'm down... syndrome."
    • In Jeffy's Homework!, Jeffy is revealed to attend "Special Needs School", despite the fact Logan has said Jeffy is not disabled. However, this has since been changed to Jeffy attending the same school as everyone else, suggesting that he is simply extremely unintelligent rather than mentally retarded.
  • In Jeffy Gets Bullied!, it is revealed that Jeffy's belief that 8-4=8 is now being taught as fact, under the name "Jeffy's Law of Mathematics."
    • He also thinks 2+2= Baby 2, 0+0=2 and 9+3=93.
  • His constant abuse by Nancy may be the reason for him treating Mario badly.
  • In the Pokémon series, Jeffy owns a Cookie Monster and somehow taught it Thunderbolt.
  • The first video where Jeffy is first seen without his helmet is Where's Jeffy?.
  • Jeffy has many different poses in the videos' custom thumbnails.
  • The song that is used for when he is on-screen is called Doh De Oh by Kevin MacLeod.
  • In Jeffy's Birthday!, it is revealed that Jeffy's birthday is on August 21, and his birth year (2004) was revealed in Jeffy's Parents! after the other half of his "IF LOST" paper was recovered.
  • Jeffy is seen with his eyes bulging in Jeffy's Stupid Home Video!, Jeffy Sleepwalks!, Jeffy's Birthday!, Jeffy's Sister!, and more (including one eye).
  • From September 22, 2016 until September 27, 2016, SML was selling T-shirts for $19.99 USD and $26.11 CAD.
  • In First Day Of School!, Jeffy is shown to be in second grade, leading many people to assume he was 7 or 8. Despite being 16 years old, it could be possible Jeffy has been held back six or seven times. It could also be because Nancy never put Jeffy in school before abandoning him.
    • It has been revealed that Jeffy has passed second grade. [11]
  • It is possible that Jeffy puts his pencil in his nose because Jacques Pierre François got famous for putting paint in his nose and sneezing it out.
  • In Jeffy's Bathtime!, it is revealed that he has aquaphobia, a fear of water.
  • Because of his lack of intelligence and disobedient behavior, it's possible his mother never took him to school before he was forced to move with Mario in his apartment.
  • Jeffy has undergone several changes since his first appearance in Mario The Babysitter!.
    • Jeffy used to bang his head on the nearest surface whenever he was called a bad boy, but this seems to have subsided since 2017.
    • In earlier videos, he was unaware that his pencil was in his nose. In recent videos, he knows that his pencil is in his nose and seems to really care about his pencil as if it were his most prized possession.
    • In earlier videos, whenever he would pat his diaper, he would not respond to anything. He later stopped doing this.
    • In his first appearance, his voice sounded way more different than his new recent voice from April 2016.
    • He used to put other things besides his pencil up his nose such as a crayon or paint brush, but he later stopped doing that.
    • However, Jeffy still hates green beans and broke his promise to Mario in Jeffy's Cat Piano Problem!.
    • From that episode until now, Jeffy looks a bit different.
  • Jeffy turned 13 on the same day of The Great American Eclipse.
    • It is also revealed in Jeffy's Birthday Wish! that his birth sign is Leo.
  • On November 22, 2017, Logan uploaded a video on Chilly's channel saying that he'll make some minor changes to Jeffy, as YouTube kept on demonetizing videos that have to do with Jeffy doing inappropriate things, like humping a Cheerios box and swearing most of the time.
  • Jeffy is the second character to solve a Rubik's Cube, the first being Cody.
  • Jeffy, alongside Mario and Brooklyn T. Guy are now the most common characters in the SuperMarioLogan channel.
  • Logan has also stated in an interview with Dabhdude that he wishes that he had never added Jeffy, due to the issues that have arisen after his debut.[12] However, in SML Reacts: Jeffy's Mistake, he does admit to liking Jeffy as a character.
  • Jeffy was not originally meant to always spank his diaper. It was in Mario The Babysitter! where Lance started to make Jeffy spank his diaper out of nowhere. In fact, Logan was originally going to cut the scene of Jeffy spanking the diaper since it makes him seem as if Jeffy was masturbating, however, the majority of the cast members thought it was hilarious and started laughing hysterically so Logan decided to put it in instead, and is thus why Jeffy often spanks his diaper in his older videos.[13]
  • As announced in a Chilly vlog, Logan might not make Jeffy in SML videos anymore, that is until Jeffy Plays Baseball! appeared.
  • It is revealed in Jeffy Goes To The Zoo! that Jeffy is implied to be zoophilic.
  • He wears an Up & Up‎ newborn diaper.
  • He wants to be a grown up when he grows up.
  • It was speculated by many older fans that Jeffy's original personality was a replacement for the beloved early-generation characters Mama Luigi and Tony The Tiger because of their dumb antics. In later videos however, Jeffy's personality has changed in a way Mama Luigi and Tony never would have acted, disproving the theory that Jeffy was Mama Luigi and Tony's replacement.
  • He can't swim, as revealed in Jeffy Plays Baseball!.
  • Jeffy's favorite character on Spongebob Squarepants is Patrick. However, he believes that Patrick is Squidward.[14]
  • Jeffy's way of understanding people is the opposite of his objective.
  • Jeffy is a fan of Naruto.[15]
  • Jeffy and Goodman both curse frequently.
    • Coincidentally, both characters are voiced by Lance.
  • Jeffy can look both ways at the same time when crossing the street since he is cross-eyed.[16]
  • Due to Jeffy having used the Memory Looker Backer Machine to help finds his pencil in Jeffy Loses His Pencil!, Jeffy is now at an increased risk for brain cancer.
  • Jeffy has admitted that even though his name is written on his shirt, he still forgets his name sometimes.[17]
  • A metal rod is used for Jeffy to control his arms, that rod is usually on his left hand, implying Jeffy might be left-handed
  • Jeffy doesn't know his colors.[18]
  • It's revealed in Jeffy's Parents!, that Jeffy was born in Paris, France.
  • Jeffy's catchphrase "ARE YOU F--KING High!" could be inspired by the 2008 comedy movie Step Brothers. The movie is about two step brothers named Brennen and Dale who are adults but act like there little kids, in one scene Brennen and Dale's parents ground them by not letting them watch TV for a week after the two get into a fight witch made Brennen mad and shout "ARE YOU F--KING HIGH!"
  • in Jeffy's Lie!, he is shown to turn off his ears and pretends he cant hear anything in a form of ignoring people.
  • Jeffy has worn the most costumes out of any character on SML.
  • There is a difference between SML Jeffy and Kable10 Jeffy, the SML Jeffy would get mad or upset when he gets punished or grounded while Kable10 videos Jeffy, he would be just upset.
  • Older videos showed Jeffy frequently swearing. More recently, he stopped swearing.
    • One of the reasons why Jeffy may not swear a lot like he used to is because of YouTube and Logan not wanting his channel to be shut down or his videos getting demonetized
  • His childhood is much like Dabi's from BNHA


Logan has released merch with most of them being Jeffy related, like the Jeffy phonecase, Jeffy T-shirt and the newly added most wanted to be the Jeffy Puppet which cost approximately $99 which have currently gem discounted to $75. Most of the shirts and stuff there tend to be pretty pricey ranging from $20-$50. The Jeffy Puppet tends to be the most popular sidling about 80 puppets PER DAY. The Puppet according to Logan is a 24-inch Puppet made from plush fabric outer layer, 100% Polyester inner layer for hand-insert, stuffed with PP cotton. PU leather shoes, and non-woven diaper. The production takes up to 1 or 2 days.
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Main characters MarioBowserChef Pee PeeBowser JuniorJosephCodyRosalinaJeffyBrooklyn T. Guy
Recurring characters GoodmanJackie ChuTyroneJudyRichard GoodmanBully BillSuper DBlack YoshiShrekGod
Minor characters Doofy The DragonToadCharleyyyTony The TigerWoodyMargaretLuigiCraig The DevilScrewballMr. PigPeachThomasKenPatrickPink YoshiPrincipal SteinbeckHarold WilfredBanzai BillDonkey KongDiddy KongGolden ThomasHanselKirbyChris the CucumberFelipeThe RatEmily ColemanPixie GoblinSamanthaWarioWaluigiSimmonsBrooklyn Guy's WifeTyreeseTom BradyMr. WinkleCarlosCandyCandy's FatherMickey MouseRay CheesyD-Money JuniorJackie TwuMine! BirdScooterLoan DolphinSonicChef Poo PooChompyThe AlienDr. Fredrick FinkleshitsJacques Pierre FrançoisCrystalHarambeBarack ObamaMr. DinkleThe Alien's WifeTerranceMelvinDoes Bad Things GuyGumboDrawing JeffyMr. MagooCookie Monster
One-Time characters Dark Matter in my ShortsChef LuigiThe CrocodileElectrician's SonJoseph's GirlfriendRemySheila PerkinsPopeyeD-Money SeniorThe Cat In The HatDoofy's Ex-WifeBirdoPolly The ParrotKidnapperKatyJoseph's DadMr. BonesFeebeeJeff The KillerKiller ClownOther Killer ClownChazJunior JuniorStephen HawkingPee Pee SuckWormyNancy JeffyEaster Bunny GenieRussian SpyPiggieGreen Bean GiantPoofGreg the PigDewey DonediditCatherine CatfishBungholeShelbyKool-Aid ManBearySharkyBabiesBig BwahBoofy the MooseChester the ChickenMore...
Classic Characters Big RedKung PowBaby PeachThe RatTyreeseTaco Bell ChihuahuaMama LuigiSpeedyPimpster GoombaSkittlesShrek JuniorTalibanBlueChadKing PigRay the pigHelmet PigYoshiCeciliaKing StrongbottomTannerKoopa TroopaAtsoBrown ElephantLazlo
Cast Logan ThirtyacreLovell StantonLance ThirtyacreChris NethertonChilly JimenezElaina KeyesTito JimenezAnthony MillerMatthew ReberJulian JimenezDonald RodriguezRebecca
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