User with this ability either is or can transform into an undine, elemental beings associated with water, first named in the alchemical writings of Paracelsus. Similar creatures are found in classical literature, particularly Ovid's Metamorphoses. Later writers developed the undine into a water nymph in its own right, and it continues to live in modern literature and art. In European lore, Undines are almost invariably depicted as being female, and are usually found in forest pools and waterfalls. The group contains many species, including nereides, limoniades, naiades and mermaids.