rusalka
A female water spirit that leads handsome men to their deaths underwater.
She is now a rusalka, a water spirit; in revenge she sends their daughter, a rusalochka, to lure him into the water.
Where it comes from
From Russian руса́лка (rusálka, “mermaid, siren”). Doublet of rosalia.
Adapted from the Wiktionary entry rusalka (CC BY-SA 4.0).