“Speeding Bullets” Lex Luthos
In “Superman: Speeding Bullets,” instead of being found by the Kents, Last Son of Krypton Kal-El is instead found by Thomas and Martha Wayne, and is raised as Bruce until his parents are murdered in an alley. As the story is essentially about Superman and Batman being the same character, it makes sense that in this comic, the Joker is actually Lex Luthor.