Earlier in his criminal career, the Joker was the archenemy of the Batman. His origin was vague, and no one knew his real name.
At some point, the Joker killed Batman's second Robin Jason Todd, beating the boy to death with a crowbar.
At another point, the Joker seduced a psychiatrist at Arkham Asylum and made her his criminal sidekick Harley Quinn. The two became pregnant at some point, with Harley never mentioning the fact to her boyfriend. Instead, she spent the pregnancy at her sister's before delivering a baby girl, who she left in her sister's care. When Harley returned to the Joker's side, he didn't even notice she was missing.
Destruction of Metropolis
Utilizing Scarecrow's Fear Toxin laced with Kryptonite, the Joker tricked Superman into taking what he thought was Doomsday into space, where it was really Lois, which killed both her and their unborn son. The Joker also had a heartbeat trigger connected to her, which triggered something that the Man of Steel could not be prepared for - the destruction of Metropolis. In the middle of an interrogation between Batman and the Joker, Superman broke through and after some goading from the Joker, he killed him by punching through his chest.
The Joker's attack shook the Man of Steel, altering how he fought for truth and justice. Superman instituted a totalitarian Regime to protect the world from criminals like the Joker and vigilantes who refused to do what was necessary like Batman.
Five years after the destruction of Metropolis, a group of resistance fighters evoked the Joker's name, becoming the Joker Clan. They were temporarily lead by Harley Quinn, until she broke off to a smaller group known as the Harley Horde.  
Possible Post-Brainaic Epilogue
"I hadn't begun my day thinking I'd give a wannabe alien overlord a haircut. That was a happy accident. But what I'd first thought a distraction, inspired my life's greatest work. I found Brainiac's collection. Those poor cities from across the universe, trapped aboard his ship. There was only one thing to do! I restored them and gave Earth the reboot it so desperately needed.
I stitched together a crazy quilt of alien civilizations, without regard to rhyme or reason. Afraid, confused, devolved to their basest instincts, they kill each other in the most sickening ways. And I get to sit back, munch popcorn, and enjoy the show - watching as the world burns! Hahaha!"
Powers and Abilities
- The Joker is not officially a member of the Insurgency, given that the organization does not form until some time after his death. However, in both the mobile version and console version of the game, Joker is listed as being an Insurgent.
- 37 Appearances of Joker (Injustice)
- 5 Images featuring Joker (Injustice)
- 11 Quotations by or about Joker (Injustice)
- Character Gallery: Joker (Injustice)
This character is or was primarily an enemy of the Justice League, in any of its various incarnations. This template will categorize articles that include it into the category "Justice League Villains."
|Justice Society Villain(s) |
This character, team or organization is or was primarily an enemy of the Justice Society, in any of its various incarnations. This template will categorize articles that include it into the "Justice Society Villains" category.
|Superman Villain(s) |
This character is or was primarily an enemy of Superman in any of his various incarnations, or members of the Superman Family. This template will categorize articles that include it into the "Superman Villains category."