Chernava — Russian fairy tale character

In the Sadko bylina, Chernava appears as the one of the 900 mermaids. She is described as small, scrawny and young girl who works as a servant in the palace. When Morskoy Tsar offered Sadko a new bride, Sadko took Chernava and lay down beside her. On their wedding night he did not touch her. When Sadko was asleep, Chernava had transformed into a river, helping him to get into the human world. Sadko woke up on the shore of the river Chernava and rejoined his first wife.