In Scottish folklore, the skinless sea demon with a horse’s head and a single eye is the Nuckelavee.
The Nuckelavee is an especially fearsome creature of Orcadian folklore, from Scotland’s Northern Isles. Accounts describe a fleshless horse-like body, exposed muscles and veins, fin-like limbs, and a large equine head with a single fiery eye. Some versions add a human torso rising from the horse’s back, although descriptions differ between storytellers.
Islanders blamed the creature’s poisonous breath for withering crops, sickening livestock, droughts, and epidemics. Despite its sea-dwelling nature, it could venture onto land to pursue people. Folklore says it could not tolerate fresh water, so crossing a stream offered protection. The Mither o’ the Sea, an ancient Orcadian spirit, was said to restrain it during the summer.
The name and stories were recorded in detail by 19th-century folklorist Walter Traill Dennison. Because the Nuckelavee shares traits with water horses such as the kelpie and Scandinavian nøkk, scholars see it as a possible mixture of Celtic and Norse influences.