Bulgarian mythology: Rusalka
Rusalka is a female water spirit and sister of the samodiva. Rusalkas are eternally young and beautiful with flowing green hair. Usually they sit on the shores of rivers and lakes. They cause flood, when they tear their hair. If their skin dries out, they die. Often the souls of drowned girls, murdered and thrown in the river or dragged under water by the river sprit vodnik can become rusalkas. He is their master but they hate him and sometimes secretly help people only to confuse his plans.