Scylla the Nymph

Scylla the Nymph was a monster which appeared in the 2014 Serbian horror movie Mamula.

Description
Scylla was a type of Nymph and as such was possessed of a humanoid upper body with the tail of a sea creature. She could appear as a beautiful young maiden or, when she reverted to her true form, a being of nightmares. She was also capable of emitting a call which could make men do her bidding, although women were completely immune to her siren song.

History
First discovered in the latter half of the twentieth century by a team of divers who were attempting to excavate a tunnel between the island military base of Mamula in the Adriatic Sea and the mainland, Scylla killed most of the group. However, she became romantically attached to one who would spend the rest of his life killing and feeding tourists, and others who would not be missed, to his love.

Many years later a group of young holidaymakers visited the now-abandoned facility on an illegal sightseeing tour, and while many of them were killed by both Scylla and her guardian, the two who escaped the island managed to kill both of their assailants, though not before Scylla called for her “sisters” - many others of her kind - to visit vengeance upon her murderers.