Source: Siege of Stone, pg(s). 83
Rock tuataras, sometimes called deep crag tuataras, are the most common underground species of tuatara and plentiful in Nar-Voth, where their camouflage has adapted to cave walls and rocks. They can be up to two feet long, weigh about four pounds, and nest in groups of up to twelve. Rock tuataras can be helpful familiars in rocky environments.