Katy Perry appears in the episode "The Fight Before Christmas," which first aired on December 5th, 2010.
Restart Rock on the Simpsons
Renee, We Like You Just as You Are
Dirtbike Flips over Stunt Plane
Harry Shearer to Obama: Return The Nobel
The Monster Dolls That Killed Barbie
Ariana Grande, This Is How to Be a Diva