Michael Myers' mask from Halloween creates this effect. If you're not paying attention, or viewing it in the dark, it looks human enough. At a passing glance, you might not even notice that it isn't his actual face. But when you get a good look at it, you notice something wrong. Very, very wrong. It looks like it was based on a human face, but one rendered soulless and inhuman by some unspeakable evil. It gives the impression that Myers used to be human, but is now some horrific parody of humanity. The effect is unsettling at first, but the longer you look at it, the more it stares back, like some terrible staring contest. And the mask is never going to blink.
- Dr. Loomis' description of Michael's actual face fits this trope like a glove.
Loomis: I met him fifteen years ago. I was told there was nothing left. No reason, no, uh, conscience, no understanding and even the most rudimentary sense of life or death, of good or evil, right or wrong. I met this six year old child with this blank, pale, emotionless face, and the blackest eyes, the devil's eyes. I spent eight years trying to reach him and then another seven trying to keep him locked up because I realized that what was living behind that boy's eyes was purely and simply... evil.