This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Yomotsu-shikome (Japanese)
Yomotsu-shikome ('Ugly Woman of the Underworld'), in Japanese mythology, was a hag sent by the dead Izanami to pursue her husband Izanagi, for shaming her by breaking promise not to see her in her decayed form in the Underworld (Yomi-no-kuni). Also recorded by the name Yomotsu-hisame, the name may have been a term referring collectively to eight hags, not just one.
In addition to being ugly, they often have beast-like features such as claws, paws, pointed ears, or patches of furry hair. They usually have long black hair, sagging misshapen breasts, and wide twisted smiles. They are also ravenous, and can devour food at an incredible speed.