Yozusk were territorial beasts with rocky protrusions on their back. They had long arms which they used to exhume their prey which lived underground. They relied primarily on their sense of smell in the darkness and were nocturnal. They were incredibly strong, and many young thrill-seekers enjoyed fighting the yozusks before they went after the stronger gundarks.
They were first recorded when the Sith arrived on Dromund Kaas. By the time of the Cold War, they were a predominant species in the planet's jungles. For unknown reasons, they started behaving more violently and attacking Imperial personnel, and Sergeant Molcarrus issued a bounty for anyone willing to hunt down the beasts. In due time, they were contained once again.
- Star Wars: The Old Republic Explorer's Guide