The rock beasts were a non-sentient lifeform native to a class M planet near Motherlode. They were about a hundred meters tall (citation needed • edit) and had tough skin that made them resemble rocky mounds when they were inactive.
Two varieties were seen: four-legged and two-legged. The four-legged beasts had long snouts with two eyes, and four fingers. The two-legged beasts, which crawled on their tail-like back end, were short-snouted with three eyes, and had only two fingers. Both were similar in temperament, roar, and a tendency to assume an upright posture.