10 Terrible Mistakes That Nearly Ruined The Joker For Everyone

5. Making Him A Hero

In 1975, the Joker was popular enough that Denny O'Neil thought it would be a good idea to give him his own Batman-free book, in which he fought both heroes and rival villains. While there can be interesting Joker stories where Batman has no role or a greatly reduced one (the Batman: the Animated Series episode "The Joker's Favor" would be a classic even without the first appearance of Harley Quinn), he really doesn't work as a series regular. He can't evolve in a narrative arc, and he can't represent much of a status quo to be challenged like the traditional super-hero. Cast in a role he was never meant for, the Joker bombed like Letterman at the Oscars. The series lasted nine bimonthly issues. What Fixed It: Cancellation.