Preta

The preta is a demonic undead creature originating from Indian religious lore. The name preta is a Sanskrit word which translates to "hungry ghost". This creature is also regarded as a type of yokai by the Japanese who call it "gaki".

Overview
The preta is believed to be the corrupted spirit of a person whose life was governed by greed and jealousy. Returning from death in a state of perpetual agony, pretas are driven by never-ending hunger and thirst. The objects of their hunger vary and can include anything, usually a repugnant or unwholesome substance (eg. excrement). To the preta, such things may appear delicious, only to turn to waste and rot in their mouths.

The form of the preta has most commonly been described as humanoid, but in an emaciated, corpse-like state. Notable features include withered, spindly arms and legs and a distended belly. Their appearance is symbolic of their mentality: they have limitless appetites, but have a limited ability to satisfy said appetites as symbolized by their thin necks and small mouths. Pretas are said to be invisible to most humans, except to some individuals of a particular psychological state.