Kelpies are supernatural shape shifters that are said to haunt rivers and streams in Scotland; any sizeable body of water in Scotland has tales of kelpie warning and deaths, most notably the Loch Ness where Saint Columba banished them - and you have the origin of the Loch Ness Monster. As a shape shifter, it could take many forms but the most popular one was that of a beautiful horse that would appear to lost or scared and weary travellers who would see it as a godsend. Unfortunately, kelpies are malevolent and would use this guise to lure them to their premature deaths if they were to mount the horse. The horse would then charge into the deepest part of the water and drown them. In its human form, kelpies would hide from unsuspecting travellers and jump out at them, with their grip as strong as an ox, they would crush the life force out of them. These water spirits are also known to devour humans under water and then throw their entrails onto the water's edge. You can recognise a kelpie in its human form by the silver necklace they wear which is a bridle in its equine form. The bridle of the kelpie is the only way that you are able to tame them and if you gain possession of it, it cannot take your life. Good luck.
