Katy Perry, Martha Stewart on 'The Simpsons' Tonight

Photo: Nicole Wilder/FOX

Katy Perry will guest-star on The Simpsons tonight! In a special live-action sequence, The Simpsons transform into puppets and prepare to sneak away for a holiday in the sun, but surprise visitors Mr. Burns, Moe and his new friend, Katy Perry (guest-starring as herself), delay their getaway. Katy will be singing “The 39 Days of Christmas” with the Simpsons, Mr. Burns, and Moe, who is her boyfriend! Huh?

Tonight’s show has another special guest-star! Marge writes a letter to Martha Stewart (guest-voicing as herself) asking for help to save the family Christmas tradition in the all-new “The Fight Before Christmas” episode.

In an interview with Entertainment Weekly, The Simpsons producer Al Jean explains the reason for the live action puppets in tonight’s episode:

“Maggie has a Muppet-type DVD that no one will let her watch, so she has this puppet dream with the Simpsons, and Katy Perry shows up the way Elton John would on The Muppet Show.”

Photo: FOX

America’s favorite dysfunctional family rings in the holiday with tonight’s episode “The Fight Before Christmas” airing tonight (8:00-8:30 PM ET/PT) on FOX.