Robbie Rotten from LazyTown.
Everyone in Assassin’s Creed IV: Black Flag. The “hero” is explicitly a bad guy. You capture, burn, murder, and plunder your way to infamy with a supporting cast of characters that do the same. The antagonists’ goals aren’t initially clear, but they are dead set against the establishment of Libertalia, the pirate utopia where lawlessness is the law.
Oldboy, not the American remake of course
That gnarly looking dude from the Care Bears.
Doctor Octopus in Spider-Man 2