The Penn Plax Dragon Skull Aquarium Ornament will add dimension and whimsy to any aquarium. Features a dragon skull with jewel eyes that also doubles as a hiding spot for small fish. Made of a poly resin this ornament is washable and will not alter the color or chemistry of your tank. Safe for salt or freshwater aquariums or terrariums. Safe and non toxic Washable Will not alter water chemistry Can also be used in terrariums