Siren

Believed to be descended from a group of fay children off Nephthys Goddess of Water that got cursed by her. Although no one now remembers why. 
They have an uncontrollable ability to charm and command mortals, which is tied to the lunar cycle, with it being at its strongest during the full moon.
male children are always of the father's species while females will become Sirens.
Many Sirens have a strong affinity with sea creatures, especially as they can breathe underwater.