Ryūjin

Ryūjin (龍神, lit. 'Dragon God'), which in some traditions is equivalent to Ōwatatsumi, was the tutelary deity of the sea in Japanese mythology. In many versions Ryūjin had the ability to transform into a human shape. Many believed the god had knowledge of medicine and many considered him as the bringer of rain and thunder, Ryūjin is also the patron god (ujigami) of several family groups. This Japanese dragon, symbolizing the power of the ocean, had a large mouth. He is considered a good god and patron of Japan, since the Japanese population has for millennia lived off the bounty of the sea. Ryūjin is also credited with the challenge of a hurricane which sank the Mongolian flotilla sent by Kublai Khan. Ryūjin lived in Ryūgū-jō, his palace under the sea built out of red and white coral, from where he controlled the tides with magical Tide jewels. Sea turtles, fish, jellyfish, snakes, and other sea creatures are often seen as Ryūjin's servants.