Vacuole

Vakul (aka Va, Kul vasa, chukla, i.e. "curve") — this is a mythological character of the Komi peoples, a merman who lives in reservoirs with his family. This is the spirit of the underwater world, which has an evil character, because of which it messes with people (it may even attack and drown), but it can also help a person in gratitude for the service rendered. Vakul is served by watermen, who are called vasas. 

He can appear in the form of a whirlwind. He has long green hair, which he likes to comb, disentangling mud from them. He goes out to graze his cows on the banks of the rivers, which leave no traces.

It was believed that the family of the Vakul consists of pike, and he can turn into a pike.