10 Comic Book Characters The Joker Has Killed
6. Batman (Repeatedly)
As Heath Ledger's Clown Prince so eloquently puts it in The Dark Knight, the Joker versus Batman is the equivalent of an unstoppable force meeting an immovable object, which is why it's rare to see one of them kill the other in combat.
Mister J did, however, get to murder his long-time rival over and over again in the Emperor Joker storyline. Here, the villain gained godlike powers and used them to bend space and time to his will, creating a twisted, alternative universe.
In this reality, Bizarro is the hero of Metropolis, Superman is incarcerated in Arkham Asylum, and Batman is tortured, killed and resurrected on an endless loop so he can undergo the same festival of torments the following day.
DC couldn't get away with leaving things this way, and sure enough, Supes eventually saves the day and reverses the timeline changes the Joker wrought. But Batman bears permanent mental scars from his ordeal, or at least he would have if Kal-El hadn't enlisted the help of the Spectre to have those memories transferred to him.