Butthead is one of the two main characters of the MTV show Beavis and Butthead. Butthead is known for his constant laugh. He is also known for his AC/DC shirt. In the Beavis and Butthead videogame, Butthead's shirt says SKULL instead of AC/DC for legal reasons.
Butthead is likely the smarter of the two, but barely. Butthead often calls Beavis a "dumbass" and his favorite word appears to be "cool". Butthead is a big fan of pork rinds and nachos.