The Janitor is an old man who works at Dimmsdale Elementary School.
His job is cleaning up after kids, of course. He apparently has a doctorate's degree in Philosophy, but not much else is known about him. He Is Voiced By Fred Stoller.
Although his appearance differs slightly between his episodes, the janitor is usually depicted with gray hair and a mustache, with a teal/blue janitorial jumpsuit. He usually carries a mop with him. He seems to have a strong dislike/fear of germs.
He has appeared in several episodes, notably "You Doo" and "The Big Superhero Wish!". In The Big Superhero Wish!, he fights alongside the "normal everyday heroes" against the Nega Chin and his allies. In "Future Lost", the janitor was replaced with Crocker who was no longer a teacher in the Futuristic Dimmsdale created by Timmy's wish.
In You Doo, he is cleaning the school and is a cause of danger to Timmy Turner when he gets a hold of a Timmy You Doo doll and starts sweeping it away. In this episode he says that he has Ph. D in Philosophy.
He also appeared in the third season episode "Shiny Teeth", where he was briefly considered as a replacement to Chip Skylark and Skip Sparkypants when it seemed neither could perform their concert in Dimmsdale.