Evil Mermaids

The Mermaids are a race of half-woman half-fish that appeared as minor antagonists in Pirates of the Caribbean: On Stranger Tides.

Sailors were told from time and time that they lure their prey with their beautiful looks and singing voice to their doom, usually being drowned and/or eaten. Once they have unwitting men tricked into going underwater with them, they change from model-like beauties to horrifying monsters that attack on sight.