Leopold "Butters" Scotch is one of the other fourth grade students on South Park and got his day in the sun when Kenny was permamanelty killed during the sixth season. Butters replaced Kenny temporarily, but was soon replaced with Tweet Tweet. Now Butters is still sucked into the group's antics and is often manipulated by Cartman to join in on his evil plans.
Sometimes Butters has been known to dress up as Professor Chaos when he can't handle any more abuse to exact his revenge.
He is not a girl. He is not a man. He is something you will understand. But he would die for me.Butters
Stan: But you know, I learned something today. I used to call you guys 'Melvins,' but you're just kids, like me. We separate you in school because you talk different, or you study too hard, but we've proven tonight that we can all get along.
Butters: So you mean we can stay friends, Stan? Wouldn't that be swell, huh?
Kyle: (Walks up) Dude, I'm glad to see you. You would not believe the night I had.
Stan: You? You think you had a bad night; I had to hang out all night with these freaking Melvins!