King Wada as the Water Dragon
The Water Dragon is a giant dragon that plagues the waters of both South and North Ryoshima Coast. It kills innocent people and sinks ships, most notably the Sunken Ship. It comes from the Dragon Palace and is worshipped by the Dragonians however to Amaterasu and Issun's horror we find out that they too have no control over it and fear its now evil ways.
 Role in Plot
When Ammy and Issun first arrive in Ryoshima they find out that the waters are being plagued by an evil dragon that must be defeated. So they travel the Dragon Palace where Otohime informs them that they too fear the dragon. She also tells them of what they must do to hopefully control the beast and how it will help them on their quest.
The Water Dragon is the only thing that can break the barrier to Oni Island and it also holds the Dragon Orb. Ammy and Issun must then travel inside the Water Dragon to retrieve it, this is a single tour area only. However when they free the Dragon Orb from the Water Dragon's stomach they get attacked by a Tube Fox and after they defeat the Tube Fox they also receive the Fox Rods. The removal of the Dragon Orb kills the Water Dragon so Ammy and Issun have to race to escape with their lives.
They are met by the spirit of King Wada who tells them that he transformed into the Water Dragon to protect his people from danger. He also swallowed the Fox Rods so that Ninetails could not get them. However a bad fight with Ninetails and the evil power of the Fox Rods drove him to insanity and he started to kill people.
When they return to the Dragon Palace Otohime informs them that she can pray to the Dragon Orb so she can become the new Water Dragon, thus breaking the barrier.
During the event of Okamiden, Chibiterasu and Kurow visit Ryoshima Coast before the Water Dragon's violent attacks. They visit the Goryeo before it was sunk by the Water Dragon's vicious rampages. On the Goryeo, Otohime transforms into the Water Dragon to allow Chibiterasu and Nanami to visit Sage Shrine when they travel nine months into the past. When they first arrive on the Goryeo, they have to search it for the Captain's conch shell that he uses to summon Otohime. When she arrives, she cannot transform into the Water Dragon without the help of Chibiterasu and his Celestial Brush. As Kurow, is afraid of water, she partners Chibiterasu up with her vassal, Nanami.
As she does not use the Dragon Orb, we see that it is not essential to the transformation but rather instils the user with the energy and power they need to transform.
Kurow and Chibiterasu are still on the ship when King Wada, as the Water Dragon, attacks. The Captain forces them off the ship and refuses to let them battle as they have more important business to attend to. Kurow and Chibiterasu then fly off teary eyed as the Water Dragon sinks the Goryeon.
- When King Wada was the Water Dragon he was blue in colour however Otohime transforms into a red one.
- According to the Official Okami Artbook, Inside the Water Dragon has the reverse layout of Hana Valley.
Chibiterasu and Nanami riding on the benign Water Dragon