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Nightmare Fuel: Willy Wonka And The Chocolate Factory
The Ooompa-Loompas: orange-skinned, green-haired little demons. Your child was just mutated by a freak accident? That's terrible. Say, this will cheer you up: Men with irradiated skin singing in monotone about how he or she deserved it and how terrible a parent you are!
Even if the Oompa-Loompas themselves don't scare you, the way that they're first mentioned to the audience is pretty deeply unsettling. Think about it: a giant factory has stayed closed for decades, and absolutely no one knows what goes on inside...but every so often, people see the silhouettes of some inhuman, dwarf-like creatures in the windows, with no way of knowing what they are or where they came from. "We daren't go a-hunting, for fear of little men," indeed...
The Wonkamoblile foam scene seems to take a concept of total wackiness, the wacky car, and distort it into disturbing madness. All the odd bit make a really jarring noise to young ears but it's probably because of the way Mrs. Teavee kept screaming.
In the Gene Wilder adaptation, the scene where Grandpa Joe and Charlie drink the Fizzy Lifting Drinks and Charlie almost gets axed by the fan.
The first thing people of a certain age will mention when the topic of "things that scared the crap out of you as a child when you didn't expect it" will be the "There's no earthly way of knowing/which direction we are going" sequence of Willy Wonka and the Chocolate Factory. No child alive saw it coming. It remains one of the ultimate examples of Nightmare Fuel to this day. It even made Bravo's 100 Scariest Movie Moments list (it was #74).
Wonka: There's no earthly way of knowing... which direction we are going... There's no knowing where we're rowing... or which way the river's flowing... Is it raining? Is it snowing? Is a hurricane a-blowing? ...Not a speck of light is showing, so the danger must be growing... By the fires of hell a-glowing...is the grisly reaper mowing? YES! The danger must be growing, for the rowers... keep on rowing... And they're certainly not showing... ANY SIGN THAT THEY ARE SLOWING! RRRAAAAAAAAAAAAAAAAAAAGGGHH!
How is the boat ride anything but? You're stuck in a tunnel where you get flashes of insects crawling out of people's bodies, spiders, and a man butchering animals, all while Gene Wilder appears to be going insane.
Willy Wonka himself is pretty freaky at times — even — scratch that, ESPECIALLY — when portrayed by Gene Wilder. Aside from the aura of barely-veiled madness, the guy engineers some pretty disturbing fates for his ill-mannered guests. (Not that they didn't all deserve it, but it's still disturbing to watch.)
Sequence with the fat kid falling into the chocolate river and being sucked up into the clear tube, where he gets stuck. Drowning, suffocation, trapped in plain sight, screaming for help but unheard, seen but not helped. Abandoned to deadly fate.
Violet getting turned into a blueberry. Sure, it's funny when you're older, but when you're a kid you can only think about she might explode, and how the Oompa Loompas are pushing her out of the room, singing a song and seemingly indifferent.