Appeared in: 'The Regina Monologues' (2003). On the one hand, the Harry Potter author's guest appearance represents the worst kind of The Simpsons "HEY LOOK, A CELEBRITY!" tokenism. On the other hand, Rowling justified herself with one brilliant line...

Best line: [The sarcastic reply when Lisa asks what happens at the end of the Harry Potter books] "He grows up and marries you. Is that what you want to hear?"