Empusa

Also known as Deadly Seagulls, The Seagull, Paul Naschy's Empusa

Abel, a retired actor turned occult enthusiast, and Victor, an old sea dog, take long walks on the beach reminiscing about the old days. During one of these walks, they find a woman's arm, severed below the elbow, with a strange symbol tattooed on the wrist. Obsessed by the intriguing discovery, Abel decides to take the severed arm home and investigate the symbol.