Also known as: 灰坊主
Aku-Bouzu, literally, "Ashy Baldhead" is a Japanese monster appearing in the folk lores/stories of the Tōhoku region, and is known by different names in some regions.
This monster lives in the Ashes of a sunken hearth and leaps out at those who play around with the ash, drags them inside and eats them.
No folklore exists that tell of the appearance of an Aku-Bouzu. This is because it's one of the Japanese patterns of bogeymen.
Stories of Aku-Bouzu assaulting children who commit various acts considered "bad-manners" by adults ~such as bathing twice in a row on the same day, eating the food offered at the altar, going to the toilet naked~ also exist.