Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: Hayao Miyazaki
Hayao Miyazaki is one of the greatest anime film directors of this generation. That being said it doesn't mean that his works won't frighten you.
Spoilers for several films below.
The Castle of Cagliostro has several very frightening scenes. For anyone afraid of corpses, it's a bad movie. The protagonists end up in a dungeon filled with centuries worth of unwanted guests and they even take a nap there. Bonus points for later featuring a scene in which some characters swim through the canal inside the dungeon. Obviously, the floor of the canal is also made out of dead people.
Special mention goes out to the villain's death. The guy gets crushed between clock hands with a sickening snap kind of sound.
Laputa literally falling to pieces in the sky, with Muska being crushed and blinded. Don't forget the storm scenes, either, particularly when Pazu hallucinates his dead father's ship. There's also the scene where Muska gathers the General and other soldiers in the glass dome under the floating island and then drops the floor out from under them, they fall to their implied deaths.
The opening sequence seems specifically designed to tap into the childhood fear of being left alone in a strange place. When the hero Chihiro's parents eat some cursed food that turns them into pigs, the sun goes down, and all kinds of creepy black blob monsters flood into the streets. Chihiro runs to the river, where more weird creatures disembark from a riverboat. Finally, she starts to fade into nothing.
This movie is packed with nightmare fuel, from No Face's rampage to the creepy faceless people on the train ride.
Then there's Yubaba, whose head is scary enough on its own...then you see how proportionately huge it is to her body. Apparently, Yubaba was based physically on the original (and most famous) illustrations to Alice in Wonderland, the ones by Sir John Tenniel, such as The Duchess◊.
The corrupted No-Face rampaging around the bathhouse and, at various points, eating people, making death threats at the heroine, destroying everything in sight, and puking his guts out.
The River Spirit in the bathhouse. Its face is like a zombie's.
The three green severed head things rolling around Yubaba's office that don't talk and eventually pretend to become her child.
Watching Haku thrash about bleeding from the mouth after being attacked by a swarm of paper birds.
The theme of losing oneself. Kohaku being reduced to following rules and orders from and hating Yubaba, No Face getting..."sick" from being in the bath house, "Sen" changing so subtly over fewer than 24 hours that neither she nor the audience notices when she first ceases to realizes that she was anyone else.
Chihiro and Haku are falling through the bowels of the bathhouse, and featureless shadow-things stretch up toward them. What are those things?
The creepiest moment in the entire movie is when Chihiro is on the train (the one-way train that never returns, carrying ghosts) and it passes a station, where the ghosts get off. It's implied this is sort of a station where the spirits of the deceased enter into a new realm. Then, Chihiro watches as a little girl no older than her, also a ghost, gets off too.
Accompanied by incredible Fridge Horror; what if said little girl was in the same situation as Chihiro, but somehow failed and got herself killed?
Forget the room of lights, what's even worse is when Howl makes his contract with Calcifer in the flashback, which puts into perspective exactly what those lights are, expands the ideas of what they can do almost infinitely, and worse, tells you that they are out there somewhere and not created or under the control of any magic user. Complete with unintelligibleIronic Nursery Rhyme.
The dream Sophie had where she discovered Howl in said form and he says, "Go away." Enough to send chills up anyone's spines, especially if you recognize Christian Bale's Batman voice during the dream.
That moment when Sophie thinks that Howl is dead and the ring helps her to find him. Miyazaki always has great visual representations for magic, but liquid darkness is probably the most awesome (and one of the scarier) things that happen in anime.
The scene where Ponyo tells her father she wants to go back to Sousuke. When you think about it later, you realize that Fujimoto is basically forcibly sedating his daughter to the point of knocking her out. Her sisters look a bit freaked out themselves.
Fujimoto's minions. They're very unsettling with the distorted mumbling and the freaky eyes. And fact that they rush and submerge a five-year-old?
Anyone watching this who has experiences with little kids capturing wild animals will be consumed with anxious certainty that Sousuke is going to kill that fish. Seeing him yanking her stomach around, hammering a rock over her head, carrying her suffocated body away from water in his bare hands, then sticking her in the bushes is not a good way to build the audience's trust in a stupid little kid, Miyazaki!
There's something unsettling about the scene where Sousuke finds his mom's abandoned car. While the rest of the film was very fantastic and whimsical, (just moments before you had a five-year-old and his best-fish-friend sailing an enlarged, candle-powered toy boat) but all of a sudden Sousuke seems genuinely frightened and vulnerable, just like a real kid. The suddenness and realism of this scene, with Sousuke tearfully crying for his mom, is oddly disturbing, tapping into the fear of a kid being alone and a parent knowing their kid is alone. It's made worse moments later when Ponyo starts to change back into a fish.
The very end. Oh, sure, it's supposed to be cute: Sosuke and Ponyo the fish kiss, and Ponyo turns into a human girl, presumably permanently. But she's over the edge of a cliff when the movie ends. Think about that.