2. He Hates The Red Skull Just As Much As Captain America
When The Joker met the Red Skull during a rare Marvel/DC Comics crossover, they got along swimmingly until the Batman villain realised he had been working with a Nazi. Despite being told by Captain America's WWII foe that he would make a "superb Nazi", it turns out that even The Joker has his limits when he declared: "I may be a criminal lunatic, but I'm an America criminal lunatic!" Who would have ever had The Joker pegged as a true patriot? After attempting to kill each other and failing, the Red Skull just had one of his goons knock The Joker out from behind, robbing fans of the chance to get to see them come to blows.