Nuckelavee

The Nuckelavee is a corpse-like being that is part horse, part man, and entirely evil. It's body is devoid of skin, comprised instead of rotting, festering muscle, sinew, and aged bone; from its gaping, skeletal maw, it spews a deadly, horrendous vapor that wilts crops, kills livestock, spreads plagues, droughts, and other epidemics. The creature lives in the sea and cannot touch freshwater, forcing it into the salty depths when rain passes over. The rough seas of Orkney are home to the nuckelavee.