As Comicbook.com detailed, Luthor and the Joker teamed up in a three-part 1997 episode of Batman: The Animated Series and Superman: The Animated Series. The Joker proposes a deal to Luthor, offering to take down Superman for a substantial price. Ultimately, Superman and Batman team up and stop the dynamic duo of villains.

The same is true for some of his greatest foes, like Lex Luthor, who has LexCorp up and running and is leading the public opposition to the Man of Steel. That approach to establishing a new cinematic universe of heroes isn't conventional,

In fact, the idea of Lex Luthor and the Joker teaming up is the subject of the classic animated movie The Batman/Superman Movie: World's Finest, which marks the first crossover between Superman: The Animated Series and Batman: The Animated Series all the way back in 1997.