Noppera-bō, the faceless yōkai
The noppera-bō is a Japanese yōkai with no eyes, nose or mouth. Tales of it appear in Kyoto story collections as early as 1663 and in folk reports from many regions.
The Nihon Kokugo Daijiten, via Kotobank, calls the noppera-bō a monster whose face has no eyes, nose or mouth, and says similar tales are found in many regions. It notes that the creature is sometimes explained as a mujina or tanuki in disguise.
Japanese Wikipedia gives two early Kyoto cases. The 1663 collection Sorori Monogatari tells of one about 2.1 metres tall seen at Oike-machi, and says nothing of what it really was. The 1767 collection Shinsetsu Hyaku Monogatari places a faceless "nupperihō" at Nijō-gawara; people it attacked found thick hairs stuck to their clothes, a hint that an animal was behind it. The same article lists folk reports from Osaka Prefecture and from Kotonami in Kagawa.
English Wikipedia notes an eighteenth-century name, nupperibō, and says older versions may leave the yōkai unnamed. Lafcadio Hearn's 1904 story "Mujina", set in Edo, is one of them. Kotobank lists Koizumi Yakumo's Kaidan among the works that describe the creature.
"An 18th-century version exists which calls the yōkai a nupperibō. Old versions may not name the yōkai explicitly as a nopperabō, and this also applies to Lafcadio Hearn's short story "Mujina" (1904), set in Edo (Tokyo). Here, a man witnesses a blank-faced noppera-bō woman, flees, and tries to tell his experience to a soba noodle shop proprietor, who also turns around with a blank face and asks if that was what the man saw."
- のっぺらぼう (Kotobank: Nihon Kokugo Daijiten and Digital Daijisen Plus), Shogakukan, via Kotobank
- のっぺらぼう, Wikipedia (Japanese)