Katy Perry to appear on 'The Simpsons.' Take that "Sesame Street." Pop sensation Katy Perry, who recently appeared on an episode of "Sesame Street" in which her appearance was cut do to being too inappropriate for toddlers, is now guest starring on "The Simpsons" in which her breasts are more than welcome.

Katy will play the girlfriend of Moe the bartender in a special Christmas themed episode entitled "The Fight Before Christmas." But that's not all! It's also being reported that all of the Simpson characters will appear as puppets in live action for this particular episode which is scheduled to air on FOX December 5th.