Kelpies

From the Scottish folklore that I've heard that a creature was called a kelpie. Basically that a kelpie is a horse that lives by the water and any unweary victims comes to contact with it, like having a ride on its back that the kelpie will be dragging them into the water and change form.

So I've have that creature idea for awhile since I thought it would be a good one for the dangerous type creature for my characters universe