According to most traditions, the rusalki were fish-women, who lived at the bottom of rivers. In the middle of the night, they would walk out to the bank and dance in meadows. If they saw handsome men, they would fascinate them with songs and dancing, mesmerize them, then lead them away to the river floor to their death.
In most versions, the rusalka is an unquiet dead being, associated with the "unclean force." People who die violently and before their time, such as young women who commit suicide because they have been jilted by their lovers, or unmarried women who are pregnant, must live out their designated time on earth as a spirit.
Their eyes shine like green fire, others describe them with extremely pale and translucent skin, and no visible pupils. Her hair is sometimes depicted as green or golden, and often perpetually wet. The Rusalka could not live long on dry land, but with her comb she was always safe, for it gave her the power to conjure water when she needed it. According to some legends, should the rusalka's hair dry out, she will die.
Rusalki like to have men and children join in their games. They can do so by enticing men with their singing and then drowning them, while the children were often lured with baskets of fruit. Men seduced by a rusalka could die in her arms, and in some versions hearing her laugh could also cause death. Alternatively, they would attract men, mainly bachelors, and tickle them to death.
The rusalki were believed to be at their most dangerous during the Rusalka Week in early June. At this time, they were supposed to have left their watery depths in order to swing on branches of birch and willow trees by night. Swimming during this week was strictly forbidden, lest mermaids would drag a swimmer down to the river floor. A common feature of the celebration of Rusal'naia was the ritual banishment or burial of the rusalka at the end of the week, which remained as entertainment in Russia until the 1930s.
While her primary dwelling place was the body of water in which she died, the rusalka could come out of the water at night, climb a tree, and sit there singing songs, sit on a dock and comb her hair, or join other rusalki in circle dances. Rusalki can also come from unbaptized children, often those who were born out of wedlock and drowned by their mothers for that reason. Baby rusalki supposedly wander the forest begging to be baptised so that they can have peace. They are not necessarily innocent, however, and can attack a human foolish enough to approach them.