Exclusive: "Treehouse of Horror XXIX" is set to air this Sunday on Fox.

It’s well-established at this point: Even in a rarified tropical environment, nothing good happens inside a glass-walled circular travel pod. That lesson seems to play a part in the upcoming “Treehouse of Horror XXIX” episode of “The Simpsons,” which sees the family trapped in a “Jurassic World”-style park. The twist here seems to be that someone has infused dinosaurs with DNA from some familiar faces.

It’s the latest installment of the long-running animated series’ annual Halloween episode, a tradition that dates back to the Season 2 in 1990. This year’s edition featured prominently in the show’s San Diego Comic-Con poster, unveiled back in July. Last year’s “XXVIII” featured riffs on “The Exorcist,” “Coraline” and general cannibalism.

True to “Treehouse” form, this is just one of the segments from this year’s 29th edition. Aside from the dino-infused Mr. Burns shenanigans, other parts include an eating contest against Cthulhu and plants that take over the citizens of Springfield. (Lisa doesn’t look too happy about a test grade either, from the looks of things.) Fan favorites Kang (Harry Shearer) and Kodos (Dan Castellaneta) will also make their customary guest appearances, as per tradition. All three parts were written by longtime “Simpsons” staffer Joel H. Cohen, who’s now been a part of four different “Treehouse” iterations since 2001.

It’s already been a notable 30th season for “The Simpsons,” which included a long-gestating “Bob’s Burgers” couch gag in a recent episode. Upcoming guest stars for the rest of the season include Jane Lynch, Patti LuPone, and Wallace Shawn, while Lawrence O’Donnell and Marc Maron will also appear playing themselves.

Watch the full clip (including some well-placed mammoth tennis balls) below:

“The Simpsons: Treehouse of Horror XXIX” airs Sunday, October 21 at 8:00 p.m. on Fox.

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