Who is Cornholio
Cornholio is the name of Beavis' alter-ego, who surfaces and replaces Beavis' own personality when Beavis consumes far too much sugar. The name Cornholio is derived from "cornhole" an American slang term for anal sex. When Beavis turns into the Great Cornholio, he pulls his shirt up over his head and wanders proclaiming "I am the great Cornholio! I need TP for my bunghole!"
Cornholio made his first appearance in the episode "Generation in Crisis." Mike Judge and voice director Kristofor Brown realized that the character of Cornholio was funny enough to carry an entire episode, and proceeded to write "The Great Cornholio," in which Beavis' alter-ego becomes the central point. This episode is considered by many to be the pinnacle of the Beavis and Butt-Head show.
More recently, the Cornholio character has re-emerged in "Buttniks," where our boys visit a coffee shop and the "Crappuchino" again puts Beavis in Cornholio mode. Also, in "Screamers," both Beavis and Butt-Head pull their shirts over their heads in one scene, although none of the standard Cornholio lines are present in this episode.
Will we see much of Cornholio in future episodes? Most certainly. There's also a good chance that he will make an appearance in the B&B movie. One other note: When asked if there would be any new characters introduced on the show (on the AOL forum), Mike Judge responded with "Son of Cornholio." Interesting...
Okay, so Beavis can turn into "The Great Cornholio" when he pulls his shirt over his head. But what about when Butt-Head does it? To date, Butt-Head has done twice ("Generation in Crisis" and "Screamers"), while Beavis has done it in a total of four episodes. The show's creators have yet to give an official name to the character Butt-Head becomes, although I've seen several people on the net affectionately refer to him as "The Great Buttholio." and changed format.