The concept of a heroic version of the Joker dates back to Batman Vol 1 #24 where Batman travels back in time to Ancient Rome and finds The Jester who looks just like the Joker but helps Batman in his mission.
Love is in the air
While the Jokester was still a young man going by the name Jackie he had a tough life. Jackie was constantly bullied at school, even when he came home his was beaten by his father. Simply put, he was despised and everyone wanted to make his life miserable. But, that all changed when he met a pretty, blond named Eve. She was very sweet and Jackie always made her laugh. They became lovers, but one day she disappeared (later on it turns out it’s because she had become Three Face). Following the career path Eve said he’d be good at, Jackie become a comedian. Unfortunately, he was a lousy comedian nobody laughed at his jokes. Then as if an omen Owlman flew through the window of the comedy club. Owlman became his comedic shtick. Rising the ladder of fame quickly helped Owlman seek out the man who’s been poking fun at him and his teen sidekick Talon. This was unfortunate for both Jackie and his assistant Harley. Harley was killed by the masked maniac and Jackie’s face was slashed to resemble a clown. Now he calls himself The Jokester.
Duela Dent is the Daughter of Jackie and Eve, but was mostly raised by the Riddler and Three-Face. The relationship with her real father has grown strong again, until she brings in her new boyfriend, Talon. The Jokester is enraged by the fact that she’s gallivant with their enemy.
Evelyn Dent was one a beautiful young lady, but now has split personality issues much like Two-Face. She used to be Jackie’s lover and now she’s the Jokester’s lover once again.
The Riddler had created a family for himself made up of Three-Face and Duela Dent, but once the Jokester came along that seemed to fall apart. The relationship between them wasn’t as strong as it used to be.
Owlman and Talon
Owlman is the archenemy of the Jokester, much like Batman is with the Joker. He is responsible for the Jokester's transformation.
Talon causes a distance between the Jokester and his daughter for he is his enemy and it infuriates him to see his beautiful daughter galavanting around with some fool.
Countdown to Final Crisis
When the Ray Palmer search party came through Earth-3, Jokester helped save the team from the Crime Society. When the team was going to teleport to their next Earth he jumped on and was brought along to Earth-15. Jason Todd, both the Red Hood and the Batman from Earth-15, showed obvious hostilities towards him but Kyle Rayner helped to cool their rage. At the next Earth, Earth-8, the Monitor who killed his daughter, Duela Dent, showed up and attacked the group. When Jokester found out he started attacking and was perhaps killed in the crossfire between the The Monitors, the Extremists, and Monarch.
The death of the Jokester came much too soon. He was a lovable hero with problems in other universes thanks to his uncanny resemblance to a certain Joker. After only six appearances his life was ended and thus living his fans in pain. But, that great coincidence is the fact that while the Joker killed Jason Todd, the Jokester gave his live to safe him along with Donna Troy, Green Lantern and Bob the Monitor.
Unlike the mainstream Joker, Jokester's skin and hair was not disfigured, only his mouth was cut wide by Owlman I (Earth-3), suggesting that he could change the coloring back to more normal coloring if he so chooses.
Eyes: Red (originally brown)
Hair: Purple (originally black, although later dyed light brown as part of his comedic act)
Unusual Features: Mouth was slit open wide and back into a distorted grin format (though he can still grimace and frown with the distortion to his face); small flower tattoo on neck area.
In the movie Justice League: Crisis on two Earths the Jokester undergoes several changes. His name in the movie is actually The Jester and he goes under a more jester theme. His mouth doesn't appear to be disfigured either.
The Jester is one of the few remaining members left of Earth-3's Justice League. At the movie's beginning he is seen with the good Lex Luthor trying to steal the "Quantum Trigger" from the Crime Syndicate. To give Luthor a chance to escape the Jester stays behind to hold off the White Martian and hid henchwoman, an altenate version of Hawkgirl. Jester is attacked and soon defeated, Harkgirl stabbing him through the stomach with her sword. Dying, and with only"one more joke" left, he pulls out a small bomb. The Jester died in the explosion but he took the White Martian and Hawkgirl with him, not to mention a large portion of the Crime Syndicate's building.
The Jester's headquarters (disguised as a toy factory) is used later by the good Lex to hide the Justice League from the Crime Syndicate. It was here that he was shown to have had a trained monkey named Harley, who Lex sadly informs of The Jester's death.
Despite his short time on film the Jester is able to pull out a few tricks. He shows equipment like an acid-spitting scepters and explosives dangerous enough to destroy super villains. The Jester also displays some impressive acrobats in the film.