Welcome To Derry executive producer and showrunner Jason Fuchs announced through an Instagram Story that production on the It prequel series, starring Bill Skarsgard as Pennywise the Clown, has been completed. Directed by the helmer of the two It films, Andy Muschietti, the HBO show follows Pennywise as he goes on a carnage in a town with unsuspecting people. Taylour Paige, Rudy Mancuso, Stephen Rider, Jovan Adepo, Chris Chalk, and James Remar are also part of the cast.

Skarsgard is also an executive producer on the show, based on the It universe from Stephen King. Director Andy Muschietti and producer Barbara Muschietti, as well as Fuchs formed a story for Welcome To Derry based on King's novel. Building on Muschietti's vision for the two feature films, the series comprises nine episodes.

The producers consist of Barbara Muschietti, Jason Fuchs, Dan Lin, and Roy Lee—the same four from the film franchise. It reunites Skarsgard with Warner Bros. Television Studios after Castle Rock, a WBTV co-production streamed on Hulu.