Ryū.

Ryū (龍, りゅう), also read tatsu, is the Japanese dragon, a long wingless serpentine being with claws, horns, whiskers, and tremendous control over water and weather. Japanese dragons inherit much from Chinese dragon imagery, but local traditions also preserve older snake-like and riverine forms. The result is not one fixed creature but a family of dragon beings ranging from sea gods to multi-headed monsters.

Unlike the fire-breathing dragons of much European legend, Japanese dragons are primarily aquatic and atmospheric. They belong to rain, tides, rivers, lakes, and storm clouds, which is why they remain so close to shrine practice and agricultural prayer.

Ryū can bless, punish, guard, or destroy. Dragon kings such as Ryūjin rule the sea and bestow tide jewels or treasures, while river and lake dragons may demand sacrifice, respond to ritual, or become the focus of rainmaking and water-control cults. In Buddhist settings dragons protect sacred teaching, and in folklore they can transform, marry into human lineages, or seize vengeance when disturbed.

Because of this breadth, ryū is less a single character than a major category of supernatural sovereignty. Wherever water means life, travel, danger, or imperial legitimacy, dragons tend to appear nearby.