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Nightmare Fuel: Shrek
The dream that Shrek has after he "wakes up" from his other dream.
IT HAD A BABY HEAD ON A DONKEY'S FACE!
The DVD menus for Shrek the Third, especially the main menu. A bunch of curtains open, a bunch of fake clouds descend on THOUSANDS of strings (looking eerily like marionettes), and all you see is the blank, gloomy-looking, huge andnot quite real-looking stage where Charming's play takes place. No characters, no voiceovers, just that enormous and clearly artificial stage, engulfed in darkness, with sinister music playing in the background. The submenus (for extras, language selection, etc.) sort of subvert this by having some of the main characters present, but the huge menu titles meant to look like suspended stage props are still kinda creepy.
Shrek's roar. Especially when taken in context. Video here.
Watching the king and queen dissolve into nonexistence is unsettling.
Or Rumplestiltkin's falling into an eternal void...