The Kelpie, a water horse spirit of Scottish myth, they are capable of shape-shifting. They inhabit the Lochs and pools of Scotland. It is described to look like a horse, but can take a human form. Said to delight in drowning its victims.
Douglas Harper, historian and founder of the Online Etymology Dictionary, defines kelpie as "the Lowland name of a demon in the shape of a horse". It is the most common water spirit in Scottish folklore, but the name is attributed to several different forms in narratives recorded throughout the country. The late 19th century saw the onset of an interest in transcribing folklore, but the recorders were inconsistent in spelling and frequently anglicised words, which could result in differing names for the same spirit.
Commentators have disagreed over the kelpie's aquatic habitat. Folklorists who define kelpies as spirits living beside rivers, as distinguished from the Celtic lakeside-dwelling water horse (each-uisge), include 19th-century minister of Tiree John Gregorson Campbell and 20th-century writers Lewis Spence and Katharine Briggs. This distinction is not universally applied however; Sir Walter Scott for instance claims that the kelpie's range may extend to lochs. Mackillop's dictionary reconciles the discrepancy, stating that the kelpie was "initially thought to inhabit ... streams, and later any body of water." But the distinction should stand, argues one annotator, who suggests that people are led astray when an each uisge in a "common practice of translating" are referred to as kelpies in English accounts, and thus mistakenly attribute lake-dwelling habits to the latter.
Others associate the term kelpie with a wide variety of mythical creatures. Counterparts in some regions of Scotland include the shoopiltee and nuggle of Shetland and the tangie of Orkney; in other parts of the United Kingdom they include the Welsh ceffyl dŵr and the Manx cabbyl-ushtey. Parallels to the general Germanic neck and the Scandinavianbäckahäst have been observed; Nick Middleton observes that "the kelpie of Scottish folklore is a direct parallel of the [sic] bäckahästen [of Scandinavian folklore]". The wihwin of Central America and the Australian bunyip are seen as similar creatures in other parts of the world.
The mythological kelpie is usually described as a powerful and beautiful black horse inhabiting the deep pools of rivers and streams of Scotland, preying on any humans it encounters. One of the water-kelpie's common identifying characteristics is that its hooves are reversed as compared to those of a normal horse, a trait also shared by the nykur of Iceland. An Aberdeenshire variation portrays the kelpie as a horse with a mane of serpents, whereas the resident equine spirit of the River Spey was white and could entice victims onto its back by singing.
The creature's nature was described by Walter Gregor, a folklorist and one of the first members of the Folklore Society, as "useful", "hurtful", or seeking "human companionship"; in some cases, kelpies take their victims into the water, devour them, and throw the entrails to the water's edge. In its equine form the kelpie is able to extend the length of its back to carry many riders together into the depths; a common theme in the tales is of several children clambering onto the creature's back while one remains on the shore. Usually a little boy, he then pets the horse but his hand sticks to its neck. In some variations the lad cuts off his fingers or hand to free himself; he survives but the other children are carried off and drowned, with only some of their entrails being found later. Such a creature said to inhabit Glen Keltney in Perthshire is considered to be a kelpie by 20th-century folklorist Katharine Mary Briggs, but a similar tale also set in Perthshire has an each uisge as the culprit and omits the embellishment of the young boy. The lad does cut his finger off when the event takes place in Thurso, where a water kelpie is identified as the culprit. The same tale set at Sunart in the Highlands gives a specific figure of nine children lost, of whom only the innards of one are recovered. The surviving boy is again saved by cutting off his finger, and the additional information is given that he had a Bible in his pocket. Gregorson Campbell considers the creature responsible to have been a water horse rather than a kelpie, and the tale "obviously a pious fraud to keep children from wandering on Sundays".
Kelpie myths usually describe a solitary creature, but a fairy story recorded by John F. Campbell in Popular Tales of the West Highlands (1860) has a different perspective. Entitled Of the Drocht na Vougha or Fuoah, which is given the translation of the bridge of the fairies or kelpies, it features a group of voughas. The spirits had set about constructing a bridge over the Dornoch Firth after becoming tired of travelling across the water in cockleshells. It was a magnificent piece of work resplendent with gold piers and posts, but sank into the water to become a treacherous area of quicksand after a grateful onlooker tried to bless the kelpies for their work. The same story is recorded by Folklore Society member and folklore collector Charlotte Dempster simply as The Kelpie's Bridge (1888) with no mention of Voughas or Fuoah. Quoting the same narrative Jennifer Westwood, author and folklorist, uses the descriptor water kelpies, adding that in her opinion "Kelpies, here and in a few other instances, is used in a loose sense to mean something like 'imps'".
Progeny resulting from a mating between a kelpie and a normal horse were impossible to drown, and could be recognised by their shorter than normal ears, a characteristic shared by the mythical water bull or tarbh uisge in Scottish Gaelic, similar to the Manx tarroo ushtey.