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"Hey, you wanna see my pencil?

My name is Jeffy, see? It says it on my shirt, Je-ffy."

— Jeffy’s first words, Mario The Babysitter!

Jeffy François Mario is one of the three main protagonists (alongside Mario and Bowser Junior) of the SuperMarioLogan franchise. He is sometimes an anti-hero and Mario's oldest adopted son.

He made his debut on January 24, 2016, Mario The Babysitter! as the main antagonist. Ever since that day, Jeffy has been very popular, similar to Bowser Junior. Despite this popularity, Jeffy has also caused much controversy and is generally hated among older SML fans. He is the main antagonist in his debut, Mario The Babysitter, Locked Out, Jeffy's Tantrum, and Jeffy Plays Fortnite.

He is the oldest son of Nancy and Jacques Pierre François, but since Jacques Pierre François died and Nancy went to jail in Jeffy's Parents!, he is now currently the adoptive son of Mario and his wife, Rosalina.[8][9]


Jeffy was first born in a porta-potty at 7 Jeffy Street Paris, France, on August 21, 2004, to prostitute Nancy and painter Jacques Pierre François. They are both of French descents, except Jacques, who is entirely French.

At some point in his life, Jeffy moved to Florida with his parents and Feebee, his little sister, was later killed in a bike accident by Woody as their mother took her helmet to use as an ashtray, forcing Jeffy to always wear his helmet in normal life.

Jeffy was then dropped off at Mario and Bowser's apartment since his mother was tired of his antics. Jeffy lived with Mario and his family in the apartment (causing havoc around the house, especially towards Mario) 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. After being arrested for child abuse, prostitution, and much more, she still hunts for Jeffy in prison. Mario chose to officially adopt Jeffy as his son. Jeffy then resumed living with Mario and continued to cause much trouble around the house.


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".

He wears short dark blue jeans with a diaper outside of it, which he occasionally spanks. According to Jeffy, the diaper is on the outside of his pants so the diaper doesn't get dirty. Jeffy wears black Adidas sneakers. His biological appearance seems to be 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.


Jeffy's personality has gone through more changes than any other character. He started off as a mentally-challenged kid before evolving into a slightly ditzy person who swears like a sailor, explodes in anger at any slight against him, and knows a lot about perverted acts for someone his age.

He has a habit of spanking his diaper placed outside of his pants. 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" (but this doesn't happen after the episode Jeffy Loses His Pencil!). 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".

However, he could have even more of a breakdown, by using curse words and being rude towards Mario and Rosalina. He likes to put his "pee-pee" in various objects, especially Cheerios boxes, to the point where he even impregnates one somehow and develops romantic feelings for it. He is also afraid of the most 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).

Not much is known about his relationship between Junior and Joseph, despite the fact that they both called him "awesome" after once surviving a game of "Russian Roulette." 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. However, Jeffy has been shown to act smart, 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.

Later, in Jeffy's Bedtime!, he called the tall character in Green Eggs and Ham, a liar since he claimed that he liked the green eggs and ham, but the illustration clearly shows that he didn't eat the ham at all, and, despite suffering from mental retardation, Jeffy is an extremely skilled painter, the result of his late father being a famous painter. According to him, he used to live on 7 Jeffy Street before being dropped off at Mario's door. Jeffy tends to soil his pants often. 

Sometimes, Jeffy can be even more demanding than Junior, as seen in Jeffy's Bedtime!, where he demands that Mario and Rosalina make him green eggs and ham, in "Jeffy Gets Potty Trained!" when he demands that Rosalina give him marshmallows instead of peas, in "The Hitman!", where he wanted Jello after Mario gave him green beans, he refused to eat his McDonalds Chicken Nuggets because he wasn't given 20 toys and threw them away, in "Locked Out", where he demanded for 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.

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?!". Sometimes Jeffy seems to have a prankster personality as in "Jeffy's Cellphone!", where he prank calls several places, including an employee named Josh and a prostitute, and in "Shrek The Babysitter!", where he locks Shrek in the bathroom with the help of Bowser Junior.

During both of these videos, 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.

Fortunately, Jeffy has his fair share of good deeds that battle the one ones such as being considerate to Hansel in three episodes. He is most likely misunderstood after suffering pain from his biological mother and witnessing his twin sister's death which might explain his outburst problems.

Despite of all this, he is still generally more on the friendly side and the bad things he does is mostly due to his unintelligence.


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. Later, Logan claimed that Jeffy is meant to be funny like Chef Poo Poo, not mentally disabled.

Since Jeffy's Bad Word! and Locked Out was 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 young children and teenagers and adding even more controversy. After Jeffy's Parents!, many people started liking him as he had been abused by his mother, Nancy.

Jeffy's popularity grew when Jeffy The Rapper! and Jeffy's Fidget Spinner! was released, which made many young children grow fond of Jeffy and basically worship him. Later, the children constantly demanded more videos featuring their Jeffy 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, a third-grader watched Jeffy The Rapper! and was disciplined after mimicking him.

As of late 2018 and early 2019, SML lost some of his 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.


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


  • "Why?"
  • "UH!"
  • "ARE YOU F***ING HIGH?!?!"
  • "What doing?"
  • "You said Jeffy's a bad boy?!"
  • "Whoops."
  • "It slipped."
  • "I don't even know."
  • "Why you do that?"
  • "The new SML store is now open, so go check it out at SML!"
  • "My name is Jeffy, see? It says it on my shirt, Jeffy."
  • "HOW HIGH ARE YOU?!?!"
  • "I didn't have to."
  • "I didn't like it."
  • "That's so, PP!"
  • "Daddy You're high as f**k!"
  • "PAPER!"
  • ”DADDY!!!”
  • “I love you!”

Likes and Dislikes


  • Beating Up Bullies
  • Pooping in his pants
  • Marshmallows on pancakes
  • Playing his Cat Piano
  • Annoying Mario
  • Toys
  • Cheerios Box (love interest)
  • Jacques Pierre François (most likely)
  • Britknee (formerly, ex-girlfriend)
  • Prank calls
  • Bicycles
  • Pencils
  • Pokemon Cards
  • Fortnite (His favorite video game)
  • Magic Tricks
  • Guns
  • Cats
  • Board Games
  • Spanking his diaper
  • Nintendo Switch
  • Police
  • Foster's Home For Imaginary Friends 
  • Mario
  • Saying the word "" (in Jeffy's Bad Word!)
  • Making a grunt noise
  • The Bunny Do song (Hop Hop)
  • Rosalina
  • Throwing stuff
  • Jumping (on beds, trampolines, etc.)
  • Kicking everyone out of the house
  • Halloween
  • Chocolate cake
  • Junior
  • Cody
  • Joseph
  • HIT Entertainment
  • ABDL
  • 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
  • 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
  • Roast beef
  • Pizza
  • Pizza Hut
  • Beating his meat
  • His drawing self
  • Toys R Us
  • Milkshakes
  • Coca-Cola
  • Ice Cream
  • Cheerios
  • Froot Loops
  • Lucky Charms
  • Poopy Butt (Formerly named: Shitass)
  • Messes
  • Minecraft
  • 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
  • Xbox
  • Being expelled from his school
  • Lifesavers (candy)
  • Spider-man
  • 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
  • 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
  • Mickey and the Roadster Racers
  • South Park
  • Hippopotamuses


  • Green Beans 
  • Cody saying that 2 can fit in 10, 3 in 6 
  • Bees 
  • Peas
  • Toilets
  • Being called a "bad boy"
  • Spankings
  • Animals (formerly)
  • The Ticket Blaster (in Jeffy's Birthday!)
  • The Bunny Do stopping
  • Jeff The Killer 
  • Ostriches
  • Lollipops
  • Pieces of gum
  • Gummy worms (formerly)
  • Getting the flu
  • Flu shots
  • Being grounded
  • His shirt running away from him
  • Getting underpaid for his teeth
  • His helmet running away from him
  • School
  • Teachers
  • 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)
  • Dead Bodies 
  • People stealing his money
  • Flies
  • Bully Bill
  • Being called a retard
  • Bullies not following the Anti-Bullying rules
  • Losing his pencil
  • Breaking his helmet
  • The moon
  • Mario hating his rap song
  • Toad
  • Hiccups
  • Bears
  • Camels
  • Craig the Devil in his Nanny form
  • Lions
  • Spiders
  • Creepers (Minecraft)
  • Coal (which he mistakes for elephant poop in Jeffy's Bad Christmas)
  • Robber
  • 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
  • Cavities
  • Bunghole
  • His helmet (In Jeffy's Switcheroo!)
  • Summer school
  • Military School (possibly)
  • 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)
  • Makes Bad Decisions Guy
  • Tim
  • His Minecraft backpack
  • Minecraft zombies
  • Baby arugula
  • Boofy the Moose
  • Vacuuming
  • Candy corn

Criminal Record

Jeffy has been known to commit crimes. Being over the age of being arrested, these crimes could land him in jail.

Assault: In Jeffy The Rapper!, he smacks a woman and in Jeffy's Bad Christmas, he attacked Brooklyn T. Guy who was disguised as Santa Claus, along with punching Santa Claus constantly. In First Day Of School and Substitute Teacher! he threw random stuff at Jackie Chu and Mrs. Nutkiss. Jeffy's Imaginary Friend! He threw a chair at Jackie Chu. In Invisible Jeffy! He knocks out Jackie Chu. He Beats up Bully Bill a lot if he insults him.

Sexual Assault: In Invisible Jeffy! Jeffy spanked 6 girls on the butts at the beach.

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 Both Mario and Rosalina's arm with a Hammer while he was Playing Pin the Tail on the Donkey' While He's Blind.

Kidnapping/False Imprisonment: He, along with Junior and Cody captured Santa Claus and held him hostage.

Ditching: He skips school twice in Jeffy Skips School! and Jeffy and Junior Skip School!

Impersonating: In Doctor Jeffy! he faked being a doctor.

Filing a false report: In Jeffy's Bad Word!, he lied to everyone that Mario raped him when in truth all he did was spank Jeffy.

Child Abuse: In Jeffy Has Kids!, he spanked and flushed his son Jeffy Junior down the toilet. And in The Baby Project!, he electrocutes the baby, threw it around, shoots it and burns it.

Murder: As mentioned in Jeffy The Rapper!, he proudly admitted shooting an old lady. He also got Bully Bill blown up after a fight in Jeffy Gets Expelled!.

Attempted Murder: He knocked out Black Yoshi with a vacuum cleaner, in Black Yoshi's Chicken Sandwich! Along with that, In Jeffy's Backpack!, Jeffy attempted to vaporize Bully Bill with the lasers on his backpack.

Theft: As mentioned in Jeffy The Rapper!, he opened up someone's mail. In Jeffy The Rapper 2, he stole some of the prize money. He also stole a Lego man from Walmart in The Watch!. In Invisible Jeffy! he steals a sandwich in a restaurant that a man who works there was making and he also stole Goodman's money while he was searching for his wallet, causing Jeffy to be shot in the abdomen. And In Rich Mario!, he stole one of Goodman's Gold Bars.

Public Disturbance: In Invisible Jeffy! He recorded Chilly Jimenez in the restroom of Jimmy Johns.

Vandalism/Criminal Damage: Jeffy smashed Black Yoshi's Xbox one off the balcony although it was a dream in Jeffy’s Mistake, the switch console in Nintendo Switch,shattered the dishes Mario made him wash in Jeffy’s Wi-Fi Problem, destroyed the TV three times: Jeffy's Tantrum!, Jeffy Gets Hypnotized!, and Jeffy The Psychic!, and He Destroyed and Messed up Bowser Junior’s Politoad EX card in Jeffy’s Pokemon Card!. He Also Destroyed the Lamp, and a Cup with a Bat in Jeffy Plays Minecraft!. In Jeffy Plays Fortnite!, He Rage-quits and He Smashes the Keyboard and Destroys the Monitor because He was So Close to his Exile. He Also Destroyed Daddy on his Bead in Bowser Junior's Game Night 4 where He Accidentaly Woke him up.

Poaching: In Jeffy's Pet Shark! he catched a shark named Sharky and keeps it as a pet until Mario told him to return Sharky to the beach.

Credit Card Fraud: In Mr. Goodman's Credit Card!, he used Goodman's credit card to purchase $10,000 worth of v-bucks in Fortnite without Goodman's knowledge.

Prank Calling: In Jeffy’s Cellphone, he Prank Calls 911, Dominos, And Pizza Hut.

Death Count

Bowser Junior's Nerf War! (possibly)
Jeffy's Mistake! (dream only) (Blown Up by Black Yoshi)
Jeffy's Flu Shot! (possibly, off-screen)

First Day Of School! (possibly beaten to death)
Jeffy Gets Stung By A Bee! (revived after being turned into a banana)
1 2 Switch Bodies! (possibly after putting a fork in an outlet, off-screen)
The Golden Egg! (possibly beaten to death)
Jeffy's Fidget Spinner! (off-screen) (possibly bleed to death after putting "pee-pee" in the ceiling fan
Jeffy Has Hiccups! (Mario's imagination only) (Holding Breath for too long)
Jeffy's Taco Tuesday! (off-screen) (Threw explosive tacos on the couch, killing himself, Mario, and Cody)
Jeffy's Energy Drink! (revived) (heart failure)
if SML gets Ads back! (joke only) (Burned by his creator)
Ghost Jeffy! (revived) (choked by lifesavers candy)

Jeffy Goes To Disney World! (possibly died from his homemade water slide)

Forms and Variations

Sick Jeffy

Sick jeffy by jeffy jeffy-dbmsi4j

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.


Images (1)-1


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!, and Jeffy The Rapper 2.

Emo Jeffy


Emo Jeffy

Emo Jeffy is a more depressed version of Jeffy with gothic-looking clothing and hair. This variant appeared in Jeffy's Tantrum!.

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

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!.

Drawing/Play-Doh Jeffy


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.

Jeffy App Salesman


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

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 was 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 liked to say "hey fat boy, wanna fight?".

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 black hair. Although he acts like normal Jeffy, he acts slower than normal.

Old Jeffy



Mario is Jeffy's adoptive father. Mario has an apparent strong dislike of Jeffy, but deep down, he actually deeply cares about him. This is pretty much confirmed in Jeffy's Parents! However, Jeffy likes Mario. He usually calls Mario "Daddy". Mario finally adopted Jeffy after a year in Jeffy's Parents!. Mario was incredibly unhappy that Jeffy was dropped off at his apartment door and loathes the fact he has custody of Jeffy. Mario gets frustrated with nearly every video they appear in together. Most of the time, however, it seems that Jeffy annoys Mario, not on purpose. Mario had tried multiple times to get rid of Jeffy, but to no avail. Most of his attempts ended with Jeffy back at Mario's step or in the case of Where's Jeffy?, Mario going back to get Jeffy because he had Rosalina's necklace, only to find out that gave it to a squirrel. In Bowser Junior's Nerf War!, both Mario and Jeffy even made a small cameo appearance right at the end and Mario attacked Jeffy with a Nerf gun. Jeffy gets Mario into trouble often. Mario used to hate Jeffy in earlier episodes, but he deep down loves him, except for his stupidity.
Untitled by awfulfanvore-db79gt2

Jeffy with Mario

Although Mario gets annoyed with Jeffy most of the time, he has been shown to care about Jeffy, as shown in Jeffy's Mistake! when Black Yoshi was about to kill Jeffy; in Rosalina's Parents!, Mario gets scared when he assumes Jeffy fell to his death and freaks out when Jeffy gets abducted. It's possible Mario might only care just so Rosalina won't break up with him. Despite all this, they deep down love each other.

Bowser Junior 

Rock paper sissors

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 both 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!. Despite this, they appear to generally be on good terms regardless.


Jeffy's mom, whose name is Nancy, debuted in Jeffy's Parents!, and she was shown to be very abusive towards him, to a much higher extent than Mario was. Nancy acted like 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. The original puppet was made by Evelinka from Beacon Art Studios (Eva Gronowitz).


Jeffy and Rosalina seem to get along well, especially on Rosalina's side. She 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. He will yell at her occasionally if he does not get his way.

Jacques Pierre François

Not much is known about Jeffy's relationship with his dad, world-renowned French painter Jacques Pierre François, who had died 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. The original puppet was made by Evelinka from Beacon Art Studios (Eva Gronowitz).


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, somehow. 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, three years ago. The original puppet was made by Evelinka from Beacon Art Studios (Eva Gronowitz).

Brooklyn T. Guy

Most of the time, the Brooklyn 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. However, in the third episode of Who Wants To Be A Millionaire?, Brooklyn Guy is shown to get annoyed with Jeffy's behavior.

Chef Pee Pee

Jeffy seems to like Chef Pee Pee. Chef Pee Pee, however, does not seem to have the patience for Jeffy, almost as much as Mario; 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 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.

Black Yoshi

Black Yoshi and Jeffy have only unofficially met in one video Jeffy's Mistake! but that video, however, is just a dream. However, Black Yoshi and Jeffy has mention each other many time in later episodes like Jeffy's Piggy Bank! and they seem to rather have more of a positive relationship rather than a negative one. Jeffy doesn't seem to have much of a relationship to Black Yoshi.


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 on the bathroom with the toilet clogged.


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.

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.


Not much is known about their relationship, other than they don't like each other.

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.

Future Prediction

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 beating Bully Bill 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.


  • 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's favorite foods are carrots and chocolate cake as revealed in Lance's Character Q&A video.
    • He also likes pancakes with marshmallows.[10]
  • According to Logan, the 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 likes Mashed Potatoes.
  • Jeffy's full name; Jeffy Jeffy is a reference to Mario's full name; Mario Mario
  • It has not been confirmed if Jeffy is mentally disabled and retarded.
  • In Jeffy's Homework!, Jeffy is revealed to attend "Special Needs School", despite the fact Logan has said Jeffy is not disabled. 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.  
  • Jeffy's original address is 7 Jeffy Street, Paris, France.
  • He has been constantly abused by Nancy, his mother (which in turn may be the reason for him treating Mario badly).
  • Jeffy is 15 years old (as of 2019, birthday is the 21st of August) and is of French descent.
  • In the Pokémon series, Jeffy owns a Cookie Monster and somehow taught it Thunderbolt.
  • Despite being slightly unintelligent, Jeffy is still able to do many impressive acts, such as accurately painting the Mona Lisa on his Easter egg, finding a golden egg even though Mario threw it away, saying the full alphabet backwards, and getting random articles of clothing or random objects in general out of thin air.  
  • The first video where Jeffy is first seen without his helmet in 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.  
  • The original puppet was made by Evelinka from Beacon Art Studios (Eva Gronowitz) the puppet can be found on the Evelinka @Etsy website. The puppet on Etsy costs between $275 to $500.
  • 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 Canadian dollars. This was revealed in Jeffy's Sister!. However, this could've been-replaced by the sml merch store.  
  • 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 15 years old, it could be possible Jeffy has been held back 6 or 7 times. It could also be because Nancy never put Jeffy in school before abandoning him.
  • 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. 
  • Eleven seconds in, you can see a possible early version of Jeffy in the SuperLuigiLogan video, Puppet Closet! This puppet was used for Timmy in The Christmas Special!.
  • 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 has 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!.
  • Jeffy became 13 (a teenager) 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.
  • Smart Jeffy is the second character to solve a Rubik's Cube, the first character being Cody.
  • Jeffy, alongside Mario and Brooklyn T. Guy are now the most common and used 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.[11] 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.[12]
  • 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 May be zoophilic.
  • His favorite food is chocolate cake and carrots.
  • In Lance Thirtyacre's Meet the Cast video, it is revealed that Jeffy was originally going to be named Doofy, however, they already had Doofy The Dragon, so they ended up with naming him Jeffy.
    • Coincidentally, both Doofy and Jeffy are played by Lance and have somewhat similar voices.
  • In Meet the Cast video it's revealed he was originally going to be voiced by Chris but due to voicing Brooklyn T Guy he couldn't voice Jeffy since it would be hard for him.
    • Jeffy was actually supposed to have a red helmet but never happened.
  • When the SML crew first got Jeffy he never had a diaper, pencil in his nose and didn't have the name Jeffy on it.
  • He wears an Up & Up‎ newborn diaper.
  • Jeffy prefers cats over dogs as revealed in Lance's Character Q&A video, this is evident with how he frequently plays with his Cat Piano.
  • He wants to be a grown up when he grows up.
  • It has been revealed that Jeffy has passes Second grade [13]
  • It was speculated by many old fans that in his original personality Jeffy 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 color is a carrot as revealed in Lance's Character Q&A video.
  • 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.
  • It is shown in "Jeffy's Bathtime!", that Jeffy may have hydrophobia, a fear of water.
  • Jeffy is a fan of Naruto.[15]
  • Based on his statement in Bowser Junior Kinda Goes Camping!, it is possible that Jeffy is the way he is because he has Down syndrome, since he states "I'm down...syndrome.".
  • He swears a lot similar Goodman. Coincidentally, both characters are voiced by Lance.
  • It is revealed in Lance's Character Q&A video that the reason Jeffy spanks his diaper is because it "feels good on his pee pee".
  • Due to him being cross eyed, Jeffy can look both ways at the same time when crossing the street.[16]
  • Due 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
  • In Lance's Character Q&A, Jeffy is asked if he has laughed, and he says he never laughed. Which is not true, since Jeffy in First Day Of School! You see him laughing with Junior, when he put on his name card "Poopy Butt", and in Jeffy's Trap!, Jeffy 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.
  • 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 2 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 2 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.

The "Fate" of Jeffy

It has been confirmed by Logan in a Chilly vlog that when SuperMarioLogan gets ads back, he would make a video where he burns the Jeffy puppet outside because of all the trouble he's caused to both SuperMarioLogan and SuperLuigiLogan, (and to himself in general) and will even kill the character off. He's also stated that when he gets ads back, he'd upload the long-awaited SuperMarioLogan Movie and will upload Bowser Junior and other characters’ videos.

This however was later confirmed to be just a joke. And Logan has keep saying many times that he will kill off Jeffy but he always jokes about it, which means Jeffy is still alive.[19]


Logan has release many new merch with most of them being Jeffy related like the Jeffy phonecase, Jeffy T-shirt and the newly added most wanted being 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.
Click this to check the website out (


  1. Jeffy's Parents! (
  2. Cite error: Invalid <ref> tag; no text was provided for refs named jeffysparents
  3. Jeffy The Rapper! ( )
  4. First Day Of School! ( )
  5. The Fender Bender! ( )
  6. Jeffy Gets a Job! ( )
  8. Jeffy gets adopted by Mario in Jeffy's Parents!.
  9. Rosalina marries Mario in Mario's New Hat!
  10. Substitute Teacher!
  11. See and
  12. "Logan Reacts: Mario The Babysitter!" SuperLuigiLogan. YouTube. March 7, 2018.
  13. "Jeffy’s Summer School"SuperLuigiLogan. YouTube Jul 4, 2018.
  14. Jeffy Gets Help!
  15. Jeffy's Imaginary Friend!
  16. Jeffy's Birthday Surprise!
  17. Jeffy Loses His Pencil!
  18. Jeffy The Psychic!
  19. "Logan Won’t Burn Jeffy Unless " Chilly. YouTube. July 14, 2018.


Do you like Jeffy?

The poll was created at 14:58 on March 2, 2018, and so far 2097 people voted.
Do you think Logan should burn the Jeffy puppet?

The poll was created at 23:21 on April 8, 2019, and so far 756 people voted.
Who is your favorite Jeffy?

The poll was created at 19:02 on February 26, 2020, and so far 66 people voted.
Main characters MarioBowserBlack YoshiChef Pee PeeBowser JuniorJosephCodyShrekRosalinaJeffyBrooklyn T. Guy
Recurring characters GoodmanJackie ChuTyroneJudy
Minor characters Doofy The DragonToadCharleyyyTony The TigerWoodyMargaretLuigiCraig The DevilScrewballMr. PigPeachThomasKenPatrickPink YoshiPrincipal SteinbeckHarold WilfredJudyDonkey KongDiddy KongGolden ThomasHanselKirbyChris the CucumberFelipeThe RatEmily ColemanPixie GoblinSamanthaWarioWaluigiSimmonsBrooklyn Guy's WifeTyreeseTom BradyMr. WinkleCarlosCandyCandy's FatherMickey MouseRay CheesyD-Money JuniorJackie TwuMine! BirdBaby MarioLoan DolphinSonicChef Poo PooChompyBully BillThe 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-WifeBirdoBully Bill's DadPolly 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 ManBearyRichard GoodmanSharkyBabiesBig BwahBoofy the MooseChester the ChickenMore...
Forgotten 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 JimenezJulian JimenezDonald RodriguezRebecca
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