Guess who did creepy 'Simpsons' couch gag?

Did you get a thrill watching this year's "Treehouse of Horror" episode of The Simpsons on Fox? If you enjoyed the couch gag from Sunday night, then you must be familiar with Nickelodeon's Ren & Stimpy. John Kricfalusi, Ren & Stimpy's creator, did this year's installment for the annual Simpsons' episode.

“His work is a very twisted homage to Hanna-Barbera, and what’s funny is he has the kids wearing Huckleberry Hound masks. We had to get clearance from the Huckleberry Hound people," Simpsons executive producer Al Jean tells EW.