Huge, endangered worm-like creatures of the 32nd century, one of which, named Molly, was rescued from couriers by Cleveland Booker and returned to a sanctuary world.
Trance worms are enormous, slug-like animals that were hunted close to extinction by the late 32nd century, when they were traded as a delicacy. They appear in the Discovery episode That Hope Is You, Part 1.
In 3188 Michael Burnham, newly arrived in the future, learns that the cargo Cleveland Booker has taken from the courier Cosmo Traitt is a living trance worm called Molly. Book uses his empathic bond with animals to calm her. When the pair are cornered, Molly swallows their pursuers, and she briefly swallows Burnham as well before spitting her out.
Book delivers Molly to Sanctuary Four, a protected world where others of her kind live in safety. The rescue shows Burnham that the gruff courier is working to preserve endangered species.