A portrayal of the Ippon-datara based on records from Kii and Kumano through Nara. It is said to be one-eyed and one-legged, but firsthand sightings are rare; in many regions a single large track left after snowfall is taken as proof of its presence. Its most notable trait is appearing on December 20, the “Hate-no-Hatsuka,” a day overlapping taboos of mountain deities and roads, effectively discouraging entry into the mountains. In its link to smithing, folklore explains the one-leg one-eye form as derived from the tatara blower treading the bellows with one foot and watching the furnace with one eye. In the Obagatōge lineage it is equated with the oni-god Inosasao, once a terror of the peak but sealed by a monk and released only once a year. In Kumano and Itsukushima it is said “only footprints appear, not the body,” feared yet seldom directly harmful. While stories of one-legged snow spirits (such as Yuki-nyūdō and Yukibō) have blended with it, this entry centers on the Kumano–Nara stream, emphasizing three points: the taboo day, the single track, and the blacksmith-origin theory.