Monsters You Can't See

If you recall the original Predator movie from 1987, the alien was ugly, but we didn't know that for most of the movie. It used a cloaking device that rendered itself invisible. All we could see were some strange digital glitches over the background that instilled plenty of dread. That's the same type of fear engendered by the hidebehind, a monster you never saw because it would hide behind a tree... until it was too late for you to escape. The legend of the hidebehind grew among American lumberjacks to explain why some loggers never came back to camp. The only defense against a hidebehind was a drink or two of alcohol, although it stands to reason that drinking alcohol was more likely the cause of the hidebehind. 

However, the hidebehind is far from the only monster you can't see. I know, you don't see any of them, but that's beside the point. Still, some monsters defy description even in the legends because they are invisible, hiding, or will kill you if you look at them. Dr. Emily Zarka of Monstrum explains why monsters you don't see are even more terrifying than the ones you see.