If you saw the actor who brought the Predator to life walking down the street, would you recognize him? Probably not. Because behind every alien and beneath every sci-fi mask, there's a human actor or actress we never get to see on screen.
Ever wonder about the humans hiding in plain sight? Here are just a few of them.
If you want to meet more, head over to Chicago Now for a gallery of sci-fi's most famous unseen faces.