Skinwalkers, The Anunnaki, The Krepid, Cryptids.

All supposed shapeshifters and very scary. Some people think some of these are just different names for the same thing. Some believe that they are supernatural and some think they are not supernatural at all. Just a different species that are either long gone, hiding, or extinct. And then there are those that think seeing these shadowy things are just tricks of the mind or our eyes seeing things not clearly and filling in the gaps using our fear. No matter what you believe, these things are scary.

Has anyone seem any of these or think they have? Creepy stories or your thoughts on what they could be.