Ylesian white worms were a type of worm species that dwelled in the mud of the planet Ylesia, where they originated. These worms were quite long and possessed a white color. They were a favorite food of the Hutt species.
These worms came from the planet of Ylesia, located in the Cha Raaba system within Hutt Space, a region of the galaxy. The sentient, slug-like Hutts consumed them, though a single Hutt required millions to satisfy their hunger. Jabba Desilijic Tiure, a Hutt crime lord, was observed eating handfuls of live Ylesian white worms from an overflowing basket while watching a Podrace at the Mos Espa Grand Arena in 22 BBY. On Ylesia, priests of the T'landa Til bathed in red mud containing Ylesian white worms, a discovery that horrified the Corellian smuggler Han Solo when he joined two T'landa Til in the mud around 10 BBY.
The Ylesian white worms made their debut in the 1997 novel The Paradise Snare, the initial story in The Han Solo Trilogy, authored by A. C. Crispin, although the book did not name them. The species' name and image first appeared in the 1998 reference book The Essential Guide to Planets and Moons, penned by Daniel Wallace with illustrations by Brandon McKinney and Scott Kolins.