Superdude was a character played by Kenan Thompson in the first five seasons of All That. As the name and outfit suggest, he was a parody of DC Comics' Superman. He is the alter ego of Mark Cant, a student at Durmont Junior High School. His one weakness is that he is lactose-intolerant, and thus is weakened by dairy products.
Each Superdude sketch usually began with Mark and his girlfriend Penny Lane being harassed by bullies, resulting in Mark running off to transform into Superdude and get rid of the harassers. One of Superdude's dairy-themed villains would then show up and immobilize him with a dairy product, but Superdude's friends would always come to his aid, allowing him to defeat the villain.
Below are the villains that attacked Superdude whenever he appeared:
- Milkman---Superdude's archenemy, played by Josh Server. He would be dressed in a 1950's style milkman outfit, (white long shirt and pants, and a milkman hat) and often go straight to disabling Superdude, so he could then begin his conquest of 'bothering people all over the world'. His schemes included shrinking Superdude to a child, kidnapping Santa and ruining Christmas, and flinging a gigantic scoop of ice cream at Superdude. There would always be someone to come to Superdude's aid, allowing him to defeat Milkman.
- Butterboy---Milkman's 'evil butter-in-law', played by Kel Mitchell, who attacked Superdude inside a movie theater. A villain composed entirely out of butter and angrily looked to settle the score with Superdude for imprisoning Milkman. After rubbing up against Superdude, temporarily disabling him, Superdude used his heat vision to melt Butterboy and throw his head away.
- Yogurl---A female dairy-based super-villain, played by Kel Mitchell, made out of yogurt. She attacks Superdude while inside a grocery store and flings her yogurt on Superdude. After being cleaned with a moist towelette, Superdude uses his freeze breath to freeze Yogurl and allow the store customers to enjoy some frozen yogurt.
- Superdude's Impostor---a little girl (Amanda Bynes) wearing Superdude's outfit entered a bank in order to rob it and pose as Superdude to commit crimes all over the world. Superdude caught her, but the stupid bank customers could not tell them apart. One of the bank tellers produced a pitcher of milk in order to find out who the real Superdude is, and after Superdude himself is horribly damaged, the Impostor robs the bank, but stops to get her 'free toaster'. Superdude recovers and uses his 'super butt' with a magnetic field to drag the toaster, while the Impostor is holding it, to him. The Impostor is then arrested by police.
- Cowboy---In an Old West themed Superdude sketch, Cowboy, (Kell Mitchell) a human cow, comes into the Saloon where Superdude is and attacks him with his milk spraying udders. After recovering, Superdude retaliates and ties his udders in a knot, eventually causing Cowboy to explode.
- The Dairy Godfather---A spoof of Don Vito Corleone from The Godfather, The Dairy Godfather (Josh Server) kidnaps Penny Lane (Christy Knowings) in order to lure Superdude to his hideout. It works, and The Dairy Godfather splashes milk on Superdude, allowing him to tie the hero to a conveyor belt where he will eventually be sprayed with more milk, permanently de-powering him. Penny switches the belt off, allowing Superdude to get his super strength back and defeat The Dairy Godfather.