Professor E. Gadd (Original Luigi's Mansion)

Professor E. Gadd was a inventor, scientist, and ghost hunter. He appeared to Luigi as a ghost, and told him how to rescue Mario, Shrek, and the other SML characters. He was revealed to have died before the events of the series. His life before death is mostly unknown.

Trivia:

 * He is the first SML character to be animated while in the shot of other plushes. This was because there was no Professor E. Gadd plush, so Logan improvised.