The tul are a crystalline species native to the asteroid Catopsa in the Stardoc Universe.
Enormous, solid black spirals jutted in beautiful erratic eruptions. The tul absorb heat, produces random vibrations, and is incredibly dense. The tul can absorb the heat from living beings and are billions of years old. Like the pel they are turn from a solid to a liquid easily. Though it uses its ability to entrap prey, engulfing it until the body temperature is drain and then returns to a liquid state. They are natural enemies of the pel and the Lok-Teel act as a defense against the black crystals.
- Endurance (Stardoc #3) by S.L. Viehl