The reader encounters Maturin in Stephen King’s The Dark Tower series. The benevolent cosmic Turtle is especially relevant in The Dark Tower VI: Song of Susannah and The Dark Tower, where a small ivory Turtle figure becomes part of the ka-tet’s story.
Maturin connects The Dark Tower mythology with It. In It, the Turtle is an ancient, benevolent being associated with creation and serves as the supernatural antithesis of IT. The Dark Tower books expand King’s shared cosmology, placing the Turtle within the larger mythology surrounding the Tower, the Beams, and the forces opposing destructive entities such as the Crimson King.
A common mix-up is treating Maturin as appearing only in It, because the Ritual of Chüd introduces him most directly there. Another is confusing him with Stephen Maturin, the naval surgeon from Patrick O’Brian’s Aubrey–Maturin novels; King’s character is a cosmic turtle. The listed alternatives—Salem’s Lot, Under the Dome, and Misery—do not provide the canonical Maturin connection asked about here.