The "true" Joker will show up on Fox's Gotham sometime in Season 4. David Mazouz, who plays young Bruce Wayne, revealed that the man who becomes the Clown Prince of Crime will debut at some point during the back half of this season.
"It really is one of the biggest shocks. I think it's safe to say that this kind of transition is not only the smartest thing, but the biggest kind of surprise that Gotham has thrown at its audience," Mazouz told ComicBook.com. "I'm sure we'd love to have crazy cliff hangers, but this is one that is not even on the same level as anything we've done before." Mazouz went on to say that, upon reading the twist in the script, he declared it "perfect" and believes that it will help explain how Jerome is ultimately involved in the creation of the Joker.
Cameron Monaghan's Jerome was introduced in the first season of Gotham. Like a young version of Joker, Jerome could laugh the laugh and had a creepy smile, but -- as it turns out -- he's just been a red herring this whole time. Back in January, Mazouz confirmed that Jerome is not the Joker and that the real Joker will appear somewhere down the line.
Jerome was killed off in the third episode of Season 2 before being revived the following year. Since then, Jerome has lost his face (literally), led a cult of his devoted followers and fought Bruce while the latter was training to be a vigilante. He's now been committed to Arkham Asylum, but the midseason finale this past December has shown that it won't be able to hold him for long.
Returning this Thursday on Fox, Gotham stars Ben Mackenzie, David Mazouz, Sean Pertwee, Robin-Lord Taylor, Donal Logue, Cory Michael Smith, Michael Chiklis, and Erin Richards.