It waits in hidden caves and hunts as often as possible, the vicious monster of caverns across the world. It is rarely seen, it's slim body having bones flexible and small, it can slip between the tiniest cracks in the ground and passes through the trees with barely a whisper. Older than man, this creature has no name in history, but for the few that know it exists call it the Beautiful Terror.
It has no need for much sustenance beyond the souls of the dead it tears apart with it's small but sharp claws and talons. It has no stomach or reproductive parts, but it consumes the dead whole, after tearing the flesh. After the flesh of it's victim is dissolved by the acid in it's chest, the bones clatter to the ground, but it keeps the skulls. The souls of the dead are trapped in the skulls, not for food, but as eggs. Over a thousand years, the souls of the dead are warped, twisted, become dark and deadly. As the life wanes from the Terror, the new soul rises up, forces the old soul out, usually travelling to hell, and overtakes the flesh. When the flesh is old, that is the worst time to be with the creature. As the new soul rises, it senses the weakness and absorbs the blood of it's victim. As it does, it needs to either flee or fight the old Terror. They are solitary creatures, if remaining too long together they will destroy each other. Not through violence but love. As the desperation of wanting to live happens in each soul, the will attempt to merge with each other, and if successful, cause large explosions, killing the souls, rendering them into nothing. No longer existing. At all. Not heaven or hell, just nothing. If unsuccessful, one is killed, the other damaged, and will hibernate. If hibernation is successful, it will live, if not, it will also die.
No good comes from these creatures, no redemption, hell, pain, suffering, or ceasing to exist.