The Joker is the mocking mountebank of malice and uses his criminal genius to plot elaborate capers. He masks his deadly weapons as innocent looking props such as joy buzzers that deliver electric shocks and a lapel flower that sprays his Laughing Gas. The Joker teamed himself with the Penguin, Riddler and Catwoman. They sneaked into the Gotham Palace and took the places of the musical guests, Hector and the Ho Daddies. The teenagers in the audience prepared to rush them but Joker grabbed his guitar and fired streamers that wrapped them up like rope. Upon hearing police sirens, Joker cued his allies to leave. The villains stole the Replica Ray from the Acme Atomic Energy Laboratory after Joker sprayed Professor Nichols and his colleagues with Laughing Gas but Batman and Robin arrived. While Batman was dazed and seeing three Catwomen, the villains attempted to get away in the Jokermobile. They returned to the abandoned Fitzsimmons Frozen Food Factory to decide what to do with the Replica Ray.
The Joker didn't care what they did, just as long as it had a funny punch line. Joker, Riddler, and Penguin secretly plotted to use the Replica Ray as a distraction while they executed an art heist. The Joker secretly slipped his Laughing Gas into Catwoman's Batnip. It would turn Batman into an egomanic and give them the window to execute their plans in secret. The Joker activated his latest deathtrap and left Batman and Robin on giant TV dinner headed for a giant oven. Joker, Penguin, and Riddler switched places with their clones, who went with an unwitting Catwoman on a Belgravian space shuttle to an abandoned space station. The villains' clones came up with a plan to duplicate Earth so each villain would have a Gotham City to rule. They turned on Catwoman, anticipating her soft stance on Batman, and tried to vent her out Airlock 1 but Batman saved her. Batman shocked them by giving them the same fate. The Penguin cited he had to follow a set of rules by the Marquess of Queensberry. Batman cited they were outside the jurisdiction of Gotham City.
Batman beat the trio into submission. The clones, still believed to be the originals, were imprisoned at Gotham State Penitentiary and did hard labor. All the while, Batman became an egomaniac from being exposed to Catwoman's Batnip. Eventually, the clones of Joker, Riddler, and Penguin expired in prison and combusted into piles of yellow muck. While Robin and Catwoman battled Batman and his clones, the villains robbed museums of their most priceless treasures and irreplaceable artwork. Joker stole a clown painting and planned to increase its value by bumping off the artist. They hopped on Penguin's giant rocket umbrella and retreated to Penguin's Pengyblimp once a cured Batman arrived with Robin and Catwoman. During the battle, Joker donned his joybuzzer.
As the battle turned in the heroes' favor, Joker bid them farewell with a fart and bounced off the blimp's beak. He landed in the Big Top Circus main tent. He bounced off a trampoline, swung away by trapeze artists, landed in a cannon, shot into a bear juggling balls while standing on a bigger ball then got trampled by elephants. A clown police car zoomed into the center ring and captured the Joker. The Joker was reduced to tears as the car took off.