"I'm down to my last joke anyway, but this one will kill ya!"
- The Jester's last wordsThe Jester is a minor protagonist in the DC Justice League: Crisis on two Earth's. He is an alternate reality version of the famous DC villain The Joker. He is seen in the beginning of the film aiding his reality's version of Lex Luthor in stealing a quantum trigger that will allow them to travel to alternate reality's and recruit heroes from those reality's to fight The Crime Syndicate of America, his reality's version of the Justice League, albeit evil versions.
Unfortunately their heist triggered a silent alarm and The Martian, the evil counterpart of Martian Manhunter and Angelique, the evil counterpart of Hawkgirl arrived to stop them. As the villains began to catch up, Jester refused to follow Luthor, hoping to instead buy him some time. When Martian and Angelique finally caught up to Jester they easily defeated him and tortured him in an attempt to regain the trigger. Jester merely said he was down to his last joke, but it would "kill them". With that, he detonated a bomb that blew up the building they were inside, killing himself, Martian and Angelique.
Later in the film, after Luthor had recruited the prime universe DC heroes to help him, they used Jester's base as a hideout and were greeted by a monkey dressed in a Harlequin costume. Luthor sorrowly said "I'm sorry Harley, The Jester's never coming back."
Unlike the DC prime universe's Joker who is selfish, cruel and sadistic, Jester is selfless, optimistic and makes jokes that are friendly in nature. But he is not afraid to face his enemies face to face and is willing to sacrifice himself for the good of the few remaining heroes in his reality. He also uses some of Joker's trademark equipment such as bombs with smiles painted on, and hydrochloric acid to eat through solid objects