"Joker Fish" were fish poisoned with an apparently non-lethal variant of Joker Venom. Due to the effects, the creatures had their faces disfigured by the venom contorting their faces into smiles. Their appearance was used by the Joker in a scheme in which he attempt to claim copyright on various fish products sold throughout Gotham City. Joker Fish have made cameo appearances after these, notably appearing at Gotham Aquarium during Batman: Three Jokers.
In Other Media
- Batman: The Animated Series: The fish and their involvement in the copyright scheme appear in the series' adaptation of "The Laughing Fish" story.
- LEGO DC Super-Villains: Joker Fish appear in several sections of the game, where they are used as an ingredient in mixing Joker's laughing gas.