Hakuja Ryuo, the White Snake Dragon King, is a figure in Japanese folk and folk-Buddhist tradition associating the white serpent with dragon-king imagery drawn from broader dragon king (ryuo) veneration found in Japanese religious practice. In folk belief, white snakes have long been regarded as sacred messengers, often linked to water deities and to Benzaiten, and by extension to notions of prosperity and good fortune. Shrines and altars dedicated to this figure exist in various regional traditions, though practices and claims associated with it vary by locality and are not part of a single standardized doctrine.