The Gashadokuro is a vengeful revenant class that overlaps with the hungry ghost classification, it is an amalgamation of skulls composed of people who died in the field, the end creation is a massive towering skeleton.
People have described the eyes as a burning yellow or green. This lines up with the common notion of vengeful human spirits having yellow eyes, which are allowed witness in wraith possessions. Where as the demonic or non human malevolent entities bare red eyes and in possessions the host will have glossy black eyes in the late stage 3 take over. Gashadokuro is proposed to stalk the countryside's at night, devouring and eating humans without thought. The tell tale sign of approach is hearing clacking of its teeth in the darkness before seeing the protruding massive yellow eyes.
When the hatred that fuels the Gashadokuro has been satiated and ceases, the colossal skeletal being will crumple and dissipate, this is an interesting aspect of how it self destructs rather than continuing to grow and evolve as negative aligned being. This presents two thoughts to me, the first being that this is more of a formed mass composed from the remaining psychic energy of ghost shells that have been shed once a spirit crosses over that may have been weaponized and gathered by lower level negative entities. The second thought is maybe this being is an unconscious reaction given purpose through its creation in the first place by a massive amount of death initiating a vortex of sorts and being driven by the death vibration. Think of hitting a tuning fork and the ripple it initiates, the Gashadokuro would be the continued ripple, not the initiating strike that bore the ripple.
The Gashadokuro is a yōkai being described in print for the first time in the mid 20th century and originating from Japanese mythology dating back to the 10th century. If they are to exist they would be fewer in number of creation due to massive battlefield deaths not being as frequent as in the past. It would also stand to reason that because this being doesn't have the ability to prolong its energy body by feeding the same way other entities do, that would make the limited new creations still not ever lasting and possibly being so rare that one would only encounter them in a place such as the Aokigahara suicide forest, or another place of similar mass death consistency.
When I think of entities and creatures of varying mythology I often look through the lenses of my paranormal experiences, training, and education background. This helps me to step outside of the story and see what is imagination of man and what is occurring phenomena, where they overlap, and what may be the most likely explanation for such a story being born in the first place. If we break down this mythological story and look at what is possible I would say that a giant skeleton stalking the lands and eating people would be world news and well documented. However, what is more likely is a force of nature that sweeps through various lands soaked in blood, tormented spirits stitched together by their aligned suffering causing visions of nightmares, strange phenomena, and mysterious deaths. What's your interpretation?