Joker
We all know the Joker and we all know that he is a mass murdering psychopath with zero empathy. But the sad reality is that no one knows what his true origins are, not even Batman (The comic book developers haven’t yet told us which story is canon). He is often recognized as Batman’s greatest enemy, killing and blowing up people in Gotham City, although when he is caught he spends most of his time in Arkham Asylum. In addition to being a deadly and a very unpredictable physical combatant, he is a brilliant and ruthless criminal mastermind. What makes the joker a real threat is that he has no real motivation in the crimes he commits, other than his sadistic desire to show people the meaning of pain and death, and the narcissism to see the world remade in his own image.
