Spoilers for IT: Welcome to Derry’s Halloween special, “A Story of Derry.”
The giant turtle seen in the sky during the episode is Maturin, a cosmic deity with a broader role in Stephen King’s fictional universe. In Welcome to Derry, Maturin is shown guiding Kino, played by Isabel Deroy-Olson, as she searches for a way to trap the creature the Shokopiwah call the Kollu — the being later known as Pennywise.
The episode establishes that Maturin battled the Kollu in space before the creature fell to Earth. After the Kollu escaped its earthly cage and began haunting the Western Woods near the Shokopiwah settlement, Kino receives instructions from Maturin about finding the cave where it landed and using the materials there to contain it. Kino makes contact with the turtle by smoking a special root she took from Mitig, played by Zahn McClarnon. Mitig had attempted to sacrifice Kino and her friends to the Kollu.
The use of spiritual and psychedelic elements to reach Maturin echoes the original IT novel. There, the turtle guides Bill Denbrough during the Ritual of Chüd, a confrontation intended to help the Losers Club defeat Pennywise. During an astral projection, Pennywise tells Bill that Maturin died after choking on a galaxy and shows him what appears to be the turtle’s corpse. Whether that death is real or a deception by Pennywise remains open to interpretation.
In The Dark Tower series, Maturin is one of 12 guardians of the Beams that support the Dark Tower and keep the multiverse stable. The turtle is also described as carrying on its back the multiverse created by Gan, the supreme deity. The source account notes that Maturin is thought to be beyond even the Crimson King’s ability to kill, leaving open the possibility that the death described in IT was either a trick or a change of form.
Whether the Maturin in The Dark Tower is the same being as the one in IT remains debated among Stephen King readers. King has not confirmed or denied that connection. In On Writing: A Memoir of the Craft, he writes that readers form their own interpretations once a story has been released.
Sources: TVLine.