Mōryō

Mōryō or mizuha (魍魎, 罔両, or 美豆波) is a collective term for spirits of mountains and rivers, trees and rocks, as well as mononoke that live in places like graveyards, or kappa and various other yōkai.

In the Compendium of Materia Medica, there is the statement "mōryō like to eat the innards of the dead.

They go underground and eat the brains of the dead, but it is said that when an oak is pressed against their necks, they die.

In the essay "Mimibukuro" by Negishi Shizumori in the Edo period, a government official named Shibata had a loyal retainer, but on one evening, said "I'm not a human but a mōryō" and resigned.

When Shibata asked the retainer for the reason, he said it was because since it was now his turn to fulfill the role of stealing a corpse, he needs to go to a certain village.