First referenced:
The Desolate Guardians (Part 6)
Additional references: 'I didn't miss the end of the world (Final part), Our Final Acts (Multiple parts)
Shadow Entities exist on a different plane of existence to the physical plane, apparently independent of the standard multiverse. While their exact nature is unknown, they first activate, then consume all of the memories of the conscious mind of their victims, in order to experience the full range of existence. They enjoy causing sadistic confusion in their victims, and generally have little to no remorse or compassion for their victims. They do not consume the soul of their victims, describing them as pitiful and tiny, but inedible.
The Shadow Entity encountered by Heath and Noah Fulmer is aware of The Crushing Fist, and has made a deal of sorts with Heath (the terms of which are currently unknown) to help various people working to fight the end of their universes. Other Shadow Entities have also been encountered by Jonathan Cortin dwelling within The Black, these have displayed very hostile intentions through sadistic psychic torture, along with violent dismemberment of anyone caught in the open when The Black arrives, via proxy physical forms (Animal Shadows).
The Shadow Entities are feared by Dream Stealers. While many varieties of Shadow Entity exist, each with widely varied traits and intentions, they have been described as being utter servants of The Hunger by the Brownshirts, and merely individual representations it. The Shadow Entities are connected to The Black (their plane of existence) and The Ink, a darkness generated by the Shadow Spheres, which themselves are a projection of the plane of existence of The Hunger.
Terms used:
gwellion - reference to Noah Fulmer, possibly the hunter personality.
ukvwaa - reference to the state of interrogation (drug induced plus shared mental/psychic probing) that Noah Fulmer, Jay, Roger and a number of others were subjected to by an unknown force.
fivhen - comparison to bug
squuar - comparison to mud
vwaal - unknown, possibly a state of being (in as such as life or death is a state of being). Apparently a negative state in which the victim can not be helped. (Also known to Heath's coworkers, although they do not explain what it means).
Traits:
Non-corporeal entity that exists on a non-physical plane, although connected to physical entities in the form of Animal Shadows. Apparently 'carnivorous', in that they consume or eat sentient minds or consciousnesses. While the Shadow Entity encountered by Heath presented an apparently hominid 'front', the overall organism is considerably larger and more complex, but shielded from being accurately described by its very nature. The Shadow Entities encountered by Jonathan Cortin are described as being colossal, with endless snake-like shadow bodies. The Brownshirts have described the Shadow Entities as independent representations of The Hunger itself, but entirely servile to it.