Stonefins are shark-like elementals made up of earth and water that can freely swim through solid earth and water alike, often attacking from ambush. A stonefin's body is mostly made of mud with many scattered flecks of stone, including a large stone on its back reminiscent of a shark's fin. When stonefins attack, the only warning that their targets get is usually a stone sticking out of the ground and rapidly moving closer. Elemental Nature. A stonefin doesn't require air, food, drink, or sleep.