Kelpie - A shape-shifting water fey in Scottish mythology, capable of appearing as a horse or a humanoid. Often mistakenly thought to haunt lochs, Kelpies are actually traditionally supposed to be denizens of natural lakes and rivers. They are dangerous. Folktales tell of them appearing as beautiful horses wandering shores, seeming to invite people-- especially children-- to ride them. Once a person climbs onto its back, a Kelpie will plunge into to water and drowns its prey.