Horrors are formed from humanity's nightmares and fears. Their roots lie in the earliest epoch of human history, when these hairless, defenseless apes lived in terror of predators, uncaring elements, and plagues for which they had no names. Over time their fears become encrusted in myth and legend: the natural human response to a recurring nightmare in their midst.
Modern Beasts theorize that every time a person dreams of monsters, that monster either already exists somewhere in the Primordial Dream (and the dream calls on ancestral memory) or is created at that moment as a Horror (if the dreamer is one of the special few whose dreams go so deep). The Horror drifts through the Dream until it reaches one of the Chambers in proximity to the waking world. Until now, it is too far away to do real harm to dreamers, but those few that are deep dreamers with a strong connection to the Primordial Dream, it can reach.
When the Horror contacts such a dreamer, it attacks them in a process called the Devouring. The soul of the human is taken and instead, the Horror either slips inside or a completely new Horror is born from the remaining nightmares and fears of the human. Either way, the future Begotten realizes that the Horror has always been their true self, and is reborn as a Beast.
Horror and Beast are one and the same, but their relationship is more complicated. In terms of Freudian psychology, the Horror is the Id, the unrestrained force of drive and need that manifests as the Hunger. The Beast cannot bargain with this force, only try to appease its need by sating it. If they fail to do so, the Horror will hunt for itself, disturbing the Primordial Dream around the Beast by causing potent nightmares. In turn, the Beast can draw upon the Horror to manifest aspects of it in the waking world, either as Atavisms or in the form of Nightmares. In their Lair, the Begotten will always manifest as the Horror.
The Begotten can get closer to their Horror by pursuing their Inheritance. During the Inheritance, the Beast can either merge with its Horror in the Primordial Dream, bringing it forth into the waking world as a real corporeal monster or transforming their Horror into a myth that will live on within the Dream.
- , p.50, 53-54, 234