I've been doing a little research about this subject as of late due to being inspired by the Nostalgia Critic's "Top 11 Scariest Performances" (don't laugh at me). What exactly does make a character scary? Emotionlessness, I think, is something that gets to me the most. Seeing a character doing something horrible but remaining completely unfeeling about it creeps me out. It makes them seem like they just don't care about the suffering they cause or if they view it as an everyday activity like mowing the lawn or something. Another thing that gets my skin crawling is characters without faces (I'm talkin' 'bout you Slender Man!). Why does this bug me? The lack of facial features usually means lack of visual emotions. If you can't see a character's emotions, you have no idea what could be going on through their head. What are they planning? What are they feeling? And most importantly, could you possibly reason with them? This seems to filter over into other things that I find scary about characters. All those slasher movie killers that wear masks make me feel a lot more uneasy than villains who show their faces all the time. Worse still is when they are masked (or faceless) and never speak. Now I can't even take cues from the sound of their voices! Yet another thing that makes a character disturbing for me is "frozen" emotions, especially if that emotion is a big crazy grin (I'm talkin' 'bout you Jeff!). Nobody should be that happy all the time. It gives me the feeling that the person is either hiding their real emotions or has lost their mental stability a long time ago. It gives me the feeling that they are unpredictable.
But I've rambled on enough. What do YOU think makes a character scary? This can be a character from a CreepyPasta story, a horror movie, or just anything (horror-related or not). Share your fears!