Hiryū (氷竜, lit. Ice Dragon) is a dragon created by Hagoromo Ōtsutsuki as a manifestation of his power. Hagoromo create Hiryū to control all forms of coldness, this includes ice, snow, and even water. Being a dragon he was hunted for by humans, so therefor he had to create himself a human form in order to not be persecuted by the humans. Living among them for some time, Hiryū stayed with this clan of relativity peaceful people. He impregnated one of the women of the clan and she had a child that possessed the powers of ice. These powers was later on known as Ice Release, making Hiryū the originator of the Kekkei Genkai. As for the clan that affiliated himself with, it was later known as the Yuki Clan.