I think everyone has a particular scene in a movie, movie character, or an entire movie that scared the crap out of them as children. Last night I stayed up very late to watch Superman II because I couldn’t remember if it was the one that had the robot lady at the end. It wasn’t. But I actually did have a nightmare about Superman II when I was little - the three people in black were hiding in my woods and somehow I’m suddenly there with them. The lady’s hands were saws. I grabbed a fallen branch and tried to hit her with it, but she took a big bite out of it instead.
Anyway….the movies/characters I found most disturbing:

1) The Movie That Must Not Be Named
My parents were watching this when it came on tv once. They wouldn’t even let me come downstairs while it was on because “it would give me nightmares”. I was furious that I couldn’t watch it so I did what all annoying children do - make all possible obvious, distracting attempts to get into the room. At one point I finally made it and the glimpse I saw horrified me for years. Reagan was puking the pea soup. Years later, I watched the entire movie at a friend’s house and couldn’t sleep for six months. I couldn’t even close my eyes much less sit in a dark room. I would freak out thinking “Reagan is sitting on my bed!” To this day, as you can see, I can’t even hear or see the name of this movie. It scares me that much.

2) The Hobbit
I hated Gollum in the cartoon version of the Hobbit. I hated his wailing! I hated his eyes, his face, his mouth, his hands….oh! horror! When The Two Towers came out, I hid my face every time he was on screen. Now I’m desensitized to him as a character on the whole. But then, Andy Serkis’ Gollum isn’t nearly as disturbing as that cartoon.

“‘Bless us and splash us, my precioussss! I guess it’s a choice feast; at least a tasty morsel it’d make us, gollum!’ And when he said gollum he made a horrible swallowing noise in his throat. That is how he got his name, though he always called himself ‘my precious.’”

3) Superman III
Who didn’t crap their pants when the robot lady walked on screen?

4) I can’t believe I forgot this one, but The Skekses from the Dark Crystal! Those things scared the living sh** out of me! The noise they made actually makes me sick to my stomach.