The Nuppeppo is passive and unaggressive. The body odor is said to rival that smell of rotting flesh. Other theories claim that the Nuppeppo is actually decaying flesh. There is a rumor that states that those who eat the flesh of a Nuppeppo shall have eternal youth.
The Nuppeppo, or "yokai" aimlessly wanders deserted streets of villages, towns and cities, often at night towards the year-end, or graveyards or abandoned temples. It is normally solitary, but there are sightings of them in groups.
Fingers and toes may be attributed as features amidst of fold of the skin.