"Treehouse of Horror XVI" is the fourth episode of the seventeenth season of the American animated television series The Simpsons.

In the sixteenth annual Treehouse of Horror, the Simpsons replace Bart with a robot son after Bart falls into a coma, Homer and various other characters find themselves on a reality show where Mr. Burns hunts humans for sport, and costumed Springfieldians become whatever they are wearing, thanks to a witch who was disqualified from a Halloween costume contest.

Artificial Intelligence, Bart winds up in a deep coma after attempting to jump out of a window into a swimming pool.

In a parody of the 1924 Richard Connell short story "The Most Dangerous Game", men from Springfield arrive at Mr. Burns' mansion to go hunting.

The hunt is broadcast on live television as The World Series of Manslaughter, with Terry Bradshaw as a guest analyst.

Just as he is about to be shot, Burns and Smithers are knocked out by Marge with a frying pan in each hand, who then hits Homer on the head for being away from home for 18 hours without calling, before they end up having make-up sex behind the astonished Bradshaw.

In a parody of The Twilight Zone episode "The Masks",[1] the citizens of Springfield dress in their Halloween costumes for a semi-annual contest party.

In anger over losing her gift certificate, she turns everyone into their costumed characters, including transforming Homer into a decapitated human, Marge into a skeleton, Bart into a werewolf, Lisa into Albert Einstein, Dr. Hibbert into Count Dracula, Apu into R2-D2, Patty and Selma into two halves of a horse, Milhouse into a bulldozer, Nelson into a racoon (despite protesting that he is the Lone Ranger, and too poor to afford the hat), Hans Moleman into a mole (though he complains that he wasn't wearing a costume), Moe into Hugh Hefner, Principal Skinner into a GI Joe (without genitalia), his mother Agnes into a southern belle, Sherri and Terri into Tweedledee and Tweedledum and Mayor Quimby into Mayor McCheese.

The segment ends as Moe and a transformed Dennis Rodman (who was in Springfield working off a speeding ticket) talk to the audience about the importance of reading.

The "I've Grown a Costume on Your Face" segment is a parody of the episode "The Masks" from the television series The Twilight Zone.