Each-Uisge
The Each-Uisge (Gaelic 'water horse') is the deadliest water horse of Scottish and Irish folklore, inhabiting sea lochs and freshwater lochs. It shape-shifts into a fine horse, pony, handsome man, or enormous bird (boobrie). If mounted, the rider's skin adheres and the each-uisge drags them to the deepest water, devouring the whole body except the liver.