A race of Russian water creatures, they have humanoid forms and are known to drown unwary travelers in various lakes and rivers. Sexually, they give Succubi a run for their money. Rusalka can be identified by their pupilless eyes; other than that, they appear human.
The only Rusalka we’ve met lives in Omaha, Nebraska (RK 174). She is a waitress at a truck stop diner; she had sunshine blonde hair, green pupilless eyes, and “amazing breasts.”