Roaming Rock is a natural formation of volcanic rock that floated up from the sea floor in the aftermath of an underwater volcanic eruption. It is inhabited by Demonocles, one-eyed giants that consume only living prey. It is carried only by the currents of the ocean, and its vicious denizens take advantage of its drift to raid seaside towns at random. In the novel Rumo and His Miraculous Adventures, Rumo of Zamonia and Volzotan Smyke are trapped on it.