Daniel Radcliffe is taking over from Robert Pattinson in Twilight, but R-Patz fans don't worry, it's only for an episode of The Simpsons!
The Harry Potter actor is starring in a Simpsons spoof on Twilight, which will be called Tweenlight.
In the special episode, Lisa falls in love with a mysterious new student called Edmund, voiced by Daniel, who happens to be a vampire.
Simpsons producer Al Jean said: "Daniel was very excited to do The Simpsons."
Katy Perry will star in a special Christmas episode.
In Tweenlight, Edmund and Lisa's romance blossoms and they leave Springfield for Dracula-la Land - leaving Homer to come to their rescue.
Katy Perry guest stars too
Daniel Radcliffe isn't the only upcoming celeb guest star - last month it was revealed that Katy Perry would appear in a Christmas episode of the cartoon series.
The American singer won't be animated though - she'll feature in a live action scene with puppets!