Since time immemorial.
The more remote the Wilderness and the more backward the civilization, the more it tends to breed bizarre, eerie, and horrifyingly grotesque events.
Sometimes they are strange rural tales.
Other times, they are ancestral warnings, legends of the strange and unnatural.
For millennia, that terrifying World has never truly left. It looms like a shadow over the hearts of humanity, its mere mention enough to make one's hair stand on end.
A record can be found in the *Annals of the Warring States*:
During the Warring States period, in Luoyuan County of the Southern Border, lived a strange folk known as the "Luotou People." They worshipped the Luotou God, and their necks could stretch, their heads could fly. By day, they were indistinguishable from ordinary people. But at night, their heads would fly off in search of blood, returning only at dawn with no memory of their deeds.
In other words.
