The Nightmare Man (1981)

A heavy fog cuts the small isolated Scottish island off from the mainland, and dentist Michael Gaffikin has just discovered a dismembered corpse on the golf links. Michael and his artist girlfriend, Fiona Patterson, assist the local law enforcements in searching for the murderer. However, as the body count rises and the surrounding circumstances turn increasingly bizarre and gruesome, everyone begins to wonder if the killer is a human or an unimaginable creature...