Martha Wayne is the Joker. Well, in an alternate reality, that is. The Flashpoint storyline shook things up in a major way for many superheroes, but Batman was one of those most changed. It was revealed that it was the young Bruce who had actually been shot that night in Crime Alley, with his parents surviving him. This led to Thomas becoming a much darker version of the Caped Crusader, and an unhinged Martha mutilating herself and transforming into The Joker. When Batman told her he had a way to fix their reality (creating "The New 52"), The Joker committed suicide upon realising that it would mean their son would grow up to become Batman.
