Moryana — Russian fairy tale character

Moryana is a female sea spirit in Slavic folklore, possibly a goddess. Moryana was a sea vodyanitsa and daughter of the Morskoy Tsar. Sometimes the moryany were said to be numerous spirits of the sea and a marine kind of rusalki, which posed a great threat to ships, but usually Moryana was represented as a single entity.
In Russia, she was also known as the Sea Tsarevna and the Tsar Maiden. It was believed that Moryana often swam deep in the sea, taking the form of a big fish and playing with dolphins. She came ashore only on quiet evenings. At this time of day she swayed on the waves, splashed in the water and fingered sea pebbles. When a storm was rising due to the Morskoy Tsar becoming angry, Moryana calmed him down, and the storm also began to subside.