A faceless yokai that echoes a traveler's song
Zunberabo
The tune drifting up the mountain path was unmistakably his own voice. He turned toward it and asked its name — and something smooth as an egg turned to answer.
Overview
Zunberabo has a smooth, egg-like face with no eyes, nose, or mouth. It appears on mountain paths at dusk humming the same tune as a passing traveler, and can also take the shape of an acquaintance to startle its victim a second time.
Encounter
It is met on a shortcut mountain path in the Tsugaru region of Aomori at nightfall. A voice matching the traveler's own song rises from partway up the slope; demanding to know who it is brings Zunberabo face to face with the traveler. It may appear again in the face of a friend sought out for help.
Lore
The tale is told as Tsugaru folklore from Hirosaki, in which a proud singer meets a faceless being on a mountain road. It is collected in Iwaya Sazanami's Daigoen, and Zunberabo also appears among the human-shaped yokai in Mizuki Shigeru's Yokai Visual Encyclopedia. It shares its blank, featureless face with the noppera-bo type of yokai found across Japan.
Traits
It announces itself with a borrowed voice before ever showing its face, revealing its smooth, eyeless, noseless, mouthless visage only the instant it is challenged. No power to kill or injure is recorded of it; its only weapon is the shock of the reveal, sometimes delivered a second time through the face of someone the victim runs to for help.
