Water Goddess Nuregami
In the gami Okami, Nuregami is the celestial brush god that rules over water. Like all the other brush gods, she is part of the zodiac, in this case, Nuregami is the snake. She grants Amaterasu the Waterspout which can be used to create a pillar of water. Later Nuregami also grants the technique of Deluge, which creates rain, and Fountain, which allows Amaterasu to activate a Mermaid Spring without having to use a coin.
In the game she appears as a snake in a big round bottle.