The April Fool also appears to draw inspiration from a variety of characters in comic book culture, such as Batman's arch-enemy The Joker. His outfit even bears a strong resemblance to the Jokers costume, complete with a Jester hat similar to Joker sidekick Harley Quinn's. The April Fool's rather dark humor is similar to that of the Joker, as is his permanent grin. His physical characteristics appear to be modeled on that of Jack Nicholson's portrayal of the Joker in the 1989 "Batman" film. Being that Butch Hartman is an avid comic book fan, and has referenced the "Batman" series, it's likely that these decisions were made in homage to the Joker.
He tried to become a Fairy Godparent in Fairy Idol but he got catapulted off the stage knocking down the security guard allowing Timmy to sneak backstage.