A Kelpie , is a shape-shifting spirit inhabiting lochs inIrish & Scottish folklore. It is usually described as a grey or white horse-like creature, able to adopt human form. Some accounts state that the Kelpie retains its hooves when appearing as a human, leading to its association with the Christian idea of Satan.
It likes to lure men and children into the water, allowing them to mount their back. The Kelpies fur was like glue and the victim would become stuck to it...the kelpie would then proceed to drown them