Sleep Paralysis

Have you ever woken up and been unable to move or do anything? That's sleep paralysis!

Sleep paralysis is usually considered to be demon-related. Of course, the soy-squad will argue that the feeling of something (spoiler: a demon) sitting on your chest that is associated with this type of paralysis is merely a psychological interpretation the mind makes of paralysis around the chest. But most scholars argue that it could easily be the other way around, which would make a lot more sense.