It sounds like it's coming from the sky because that's the nature of the screeching, it's the type of frequency it's at.

If it is coming from the sky, a flying monstrosity is carrying the thing making the noises.

It might be a Reaper. If it is a Reaper, they are crouched over, but bipedal, and wear heavy hoods. Their face is skeletal looking, if and only if they are Reapers, read the following:

The Reapers are here Flesh and blood, "technically"

They are super fast and strong. And have long tongues with needle-like points. That's how they drink blood, by opening a neck with their sharp fingers, and sticking it into the heart. While feeding the blood, they somehow send the person's Vital Aura, they're Life Force, to the flesh and blood monster that's controlling the Reaper.



Thankfully they are rare. If you see one, do not engage unless you have 6 or more people with you. And you need to fire round after round into. There bones are very strong. They are tough mofos.

If you find one during the day, that's when they're the weakest. Proceed with caution and do no underestimate them. They are dangerous enemies.

It may talk in a hissing type voice, and try to frighten and intimidate you. Don't let it it intimidate you! Be brave!