Wikipedia
is a type of Japanese dragon or legendary serpent-like creature, either found in aquatic habitat or otherwise connected to water. Some commentators perceived it to have been a water deity. It is described in the ancient chronicle Nihon Shoki, and one Manyoshu poem.
Mizuchi is also the Japanese transliteration for several types of Chinese dragons (, Kojien dictionary, 2nd. ed.), and may refer to the jiaolong or "4-legged dragon", the qiulong or "hornless dragon", and the chilong or "yellow dragon".
Daniels (1960:157) notes that rain-controlling Japanese snake deities are sometimes called dragons, but cautions that for okami and mizuchi, "it is unsafe to deduce their forms from the Chinese characters allotted to them".