A heroin addict from 1987 New York, drawn into Mid-World through one of the doors on the beach. Quick-witted and irreverent, Eddie has a gift for defusing tension through humour that masks a deep well of courage. He becomes one of Roland's most capable and loyal companions.

A civil rights activist from 1964 New York with dissociative identity disorder, drawn into Mid-World through one of the doors on the beach. Her two identities - the composed Odetta Holmes and the volatile, dangerous Detta Walker - must find a way to coexist. A wheelchair user who lost her legs below the knee in a subway accident, she becomes one of Roland's most formidable companions.

A boy from New York who finds himself drawn into Mid-World, where he becomes a companion to Roland and his ka-tet. Perceptive and brave beyond his years, Jake possesses a low-level psychic ability and bonds deeply with the billy-bumbler Oy.

A billy-bumbler - a raccoon-like creature native to Mid-World with limited speech ability - who attaches himself to Jake Chambers in The Waste Lands and becomes inseparable from him. Oy is capable of mimicking words, shows unusual loyalty and intelligence, and serves as both comic relief and emotional anchor for the ka-tet. His bond with Jake and his actions in the final book are among the series' most affecting elements.

A former Catholic priest first introduced in King's Salem's Lot, who crosses into the Dark Tower universe and eventually settles in Calla Bryn Sturgis. Callahan failed in his confrontation with the vampire Barlow in Salem's Lot and spent years wandering before finding purpose again with Roland's ka-tet. His backstory occupies a substantial section of Wolves of the Calla. He dies in Song of Susannah rather than be taken by the Crimson King's forces, choosing his own end.