Daija

is a snake demon who impersonated the Water God.

History
Dig was once a water sprite who resorted to trickery to gain power. Daija seized the Trident of Amakoi and managed to lock up the real Water God in a cave. After posing as the Water God, he began to pray on children as human sacrifices. He choose his sacrifices by having a white arrow land on the roof of the next victim's house, until it falls to the house of the village headman of the village, whose son is Tarōmaru. The headman could not accept this, so instead of sending his son to be sacrificed, his best friend Suekichi was sent.

During the Story
Inuyasha and the others arrived at the village to investigate, so Tarōmaru asked for help, which then allowed them to discover that he was the true son of the headman.

Daija realized he was duped, but Inuyasha and his friends arrived in time to save Suekichi. Inuyasha attacked him with the Tessaiga, but its power is annulled by the Trident. Daija filled the temple where they were with water, and after distract Kagome attacked him with a sacred arrow, making him lose his human form. Daija attacked Kagome, Shippō, Suekichi, and Taromaru. Inuyasha came to save them.

After Miroku and Sango were looking for the true Water God, they help to get her to Inuyasha, Daija tried to attack Sango, but Inuyasha intervened. When Inuyasha took the trident from Daija, he turned into his true snake form. Inuyasha threw the trident toward the Water God, but Daija bumped it into the water with his tail. Taromaru dove into the water to retrieve it, but Daija tried to kill him with his tail. However, Sango cut off his tail with her boomerang and dove into the water with Kirara to get Inuyasha, after which Inuyasha cut Daija in half, and Miroku absorbed him into his Kazaana.

Powers & Abilities
Daija can take on the form of a human. Daija had the ability to extend his false limbs. Like many of the snake yōkai, Daija could constrict his enemies. With the Trident of Amakoi, Daijo could create whirlpools and manipulate clouds and water at will. he was also able to nullify Tessaiga demonic aura.

Trivia

 * Another InuYasha character Orochidayū bears similar characteristics as Daija, including his appearance and outfits. The name of these two characters, Daija (大蛇) with Orochi (オロチ) respectively also having the same meaning, "serpent".