Tanrok are wyvern like beings that live in dark caves of Asoumiranz and Cirues, such as the Untorr Caverns. They are grey with yellow, gleaming eyes and a whiplike tail that has a poison barb at the end. They hang from stalactites by their feet and watch bypassers quietly. Tanrok will screech and snap at those who approach them.

The venom from their barbed tail is a crucial ingredient in Plodosil, a medical potion used for curing an inflamed pongbat.