Can you name any super villains that might be a lamb chop short of a mixed grill? The Joker is likely the number one answer to this. But there are plenty of other insane baddies. Carnage in the Spider-Man world had bonded with an insane serial killer. The Leader in the "Incredible Hulk" comics was hit with a large amount of gamma rays, and became super intelligent, but as a megalomaniac that was always trying to take over the world. Speaking of would-be world conquerors, Lex Luthor, of Superman fame was also a tad in the need of a checkup from the neck-up.