Lex Luthor

Lex Luthor is the archenemy of Superman.

History
When Milhouse wanted to prove at he should be Bart's best friend instead of Martin he wanted to give him a comic with Superman where Lex Luthor and Martin Luther team up. Bart didn't want the comic.

In a mash-up by Bart with Lex Luthor and Tex Avery you get Tex Luthor.

Homer said that he and Comic Book Guy can still be friends, like when Superman teamed up with Lex Luthor. Comic Book Guy then said that was an imaginary story written by because he wanted to get fired.