Ao Chin

This is one of the four Great Dragon Kings that is described in Chinese mythology. The other dragons are Ao Kuang, Ao Ping and Ao Shun. Together the four dragons control the rain and the sea. The four dragons are under the command of the August Person of Jade. The dragons live in a crystal palace that are at the bottom of the ocean and are tended by crayfish, lobsters and crabs as guards and by the fish as courtiers. Whenever they is a drought in China the Dragon kings to help aid in restoring the land back to normal.

John and Caitlin Matthews, The Element Encyclopaedia of Magical Creatures, 2013, Ao Chin, p 27