“Reptilicus” did it for me.
For years, every time some scientist dug up something from the ice or tundra, I was filled with dread.
And then there was The Day Of The Triffids.
Once I got over the fear of killer plants, Children Of The Corn came around and my family’s crops freaked me out.
:D
My parents didn’t let me see that kind of thing, but I managed to be thoroughly scared by “The Wizard of Oz.”