Rusalka
In Slavic mythology Rusałka was a female ghost, water nymph or succubus-like demon who lived in a lake. Her eyes shone like a green fire. Men who were seduced by her died in her arms, and in some versions her laugh can also cause death. She corresponds to the Scandinavian and German Nixie. The ghostly version of the succubus is the soul of a young woman who died in or near a lake (most ruslaki were murdered by lovers), and came to haunt that lake; this undead rusalka is not particularly malevolent, and will be allowed to die in peace if her death is avenged.
The word is generally understood to translate simply as "mermaid".
Rusalka is also an opera by Antonin Dvorak; see Rusalka (opera).
Rusalka is also a fantasy book by C.J. Cherryh.
