Nuckelavee

The Nuckelavee is one of the most terrifying creatures in Celtic folklore, originating from the Orkney Islands north of Scotland. It is a hideous hybrid — part horse, part rider — with a single enormous eye that burns with a red glow. The rider portion has no skin, exposing raw muscle and sinew, and its long arms drag on the ground with grasping fingers. The horse portion has a gaping mouth that exudes a toxic vapor. The Nuckelavee emerges from the sea during winter to spread disease, drought, and death across the land. It cannot tolerate fresh water or rain, which is said to be the only thing that can drive it back into the ocean.