Beavis and Butt-head (born 1979, according to the episode Beavis Goes to Heaven), are the titular characters featured in the MTV animated series Beavis and Butt-head.

Beavis

Beavis has an underbite and a fixated stare on his face which almost never looks straight but to the side. Beavis grunts when he laughs and his voice is reminiscent of horror film characters played by actor Peter Lorre. The more slapstick and excitable of the two leads; he is oblivious of the obvious, has a well documented pyromania obsession, and a more passive demeanor that contrasts with Butt-head's more dominant personality. Though the designated "dumber" of the two, he has a tendency to be witty and, ironically, when discussing various subjects that neither of them understand, Beavis is the more likely of the two to guess the truer mechanisms at work. Beavis also has an alter-ego named Cornholio which usually surfaces after consuming large quantities of caffeine or sugar.

Butt-head

He wears dental braces and has squinted eyes. His top gums are often exposed and he speaks nasally with a deep voice and a slight lisp, repeatedly punctuating his speech with "uhh…". Calmer, cockier, and marginally more intelligent than Beavis, Butt-head is oblivious of subtleties, but is usually 100% confident in everything he says and does — no matter how ridiculous or inane it is. The designated "leader" of the duo, he also derives pleasure from being regularly abusive to Beavis.