The Joker is the main villain in Batman Unlimited: Monster Mayhem and minor villain in Batman Unlimited: Mechs vs. Mutants.
History[]
Batman Unlimited: Monster Mayhem[]
He, along with fellow villains, Scarecrow, Solomon Grundy, Silver Banshee and Clayface, kidnapped video game designer Gogo Shoto, as part of their plan to take over Gotham City with a digital laughing computer virus that infects all technology and vehicles, and Joker makes himself mayor of Gotham while Grundy becomes the chief of the Gotham City Police Department.
After using old-fashioned brain power and technology, Batman, Green Arrow, Nightwing and Red Robin learned that the Joker is planning a parade in his honor, and tracked him and the villains down to his hideout at an abandoned pier fun park where they confront the other villains and defeated them, and rescued Gogo, while Joker freed the villains. Taking Gogo to the Batcave, Gogo gives Batman a device that will help him enter the virtual world to stop the Joker.
After learning that the Joker is planning to send his virus worldwide, Batman enters the virtual world where he confronts multiple copies of the Joker. After a digital battle with the Joker, Batman managed to overcome the villain and stopped the virus from spreading worldwide. At the same time, during Joker's parade, James Gordon, Nightwing, Green Arrow and Red Robin managed to subdue the villains into custody. Meanwhile, the Joker dons a mech suit, and Batman realizes that Cyborg is used by the Joker as a transmitter for the virus. Finding the Rose Stone in his arm, Cyborg shorts out the Joker's mech suit, causing it to crash into the sea. While the villains are taken back to Arkham Asylum, the technology around Gotham reboots, and the heroes found no trace of the Joker after he crashed into the sea. However, the Joker survived and finds himself on an island outside Gotham. As he walks into the sunrise, Joker begins planning his next plot.
Batman Unlimited: Mechs vs. Mutants[]
The Joker somehow returned to Gotham after his defeat. During Damian Wayne's time as Robin, Damian failed to stop the Joker during a previous mission with Batman, which led to Damian's humiliation on the Internet. However, the Joker was somehow apprehended by Batman and taken to Arkham. During Penguin and Mr. Freeze's break-in, they, along with Bane, Killer Croc, Clayface and Chemo, passed Joker's cell where he asks Penguin to set him free. After Penguin refused, the Joker swore revenge on Cobblepot for refusing to set him free.
After the villains' defeat, the Penguin was placed in a cell next to Joker's. After Penguin tells him that he can't get into his cell, Joker opens an adjourned door between their cells, and he gets his revenge on Penguin by beating him up.