One concept I find scary but extremely intriguing is the existence of the uncanny valley. I want to know what possible predator existed millions upon millions of years ago that caused humans to be naturally afraid of something that is almost human but just off. Was something in the past as smart as humans that it made humanoid masks? Did that creature kill humans and wear their skin? Did it just look almost like a human? If it wore a mask or human skin, what did it actually look like under it? If it just looked like that, why did it exist? why did it (I'm hoping) go extinct? Was it alien? Was a product of evolution? What the fuck was it and why does the uncanny valley exist in modern humans when there is no threat or predator that looks almost human?