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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.
Some of the violent scenes. It does get watched by viewers much younger than the target demographic, unfortunately. The opening scene has the Boar God decay and melt, as if in acid, from flesh to the bloodied bone.
A much later scene in which Ashitaka gets shot and gets a big, bloody, gaping hole in his abdomen...and he's still standing like nothing happened.
A guy blocked an arrow with his sword, and the impact ripped his arm out. Apparently, this was all due to superpowers imbued by the demon in Ashitaka's arm. Some viewers consider that violence realistic enough to stop watching.
The Kodamas. Yes, the creepy little spirits with white bodies and huge void eyes.
The Tatari Gami, the creatures turned into worm/tentacle monsters by hate, look so truly toxic. Touch one, and your features melt into squirming black glop. San screaming "I don't want to be a demon!" and getting drawn into the sea of muck didn't help. And those huge black insta-kill blobs of Forest God neckflesh? Just as bad, if not worse.
The Forest God as a not-a-deer, with the stretchy neck and a flat face. And then it turned into a Humongous Mecha of a see-through critter.
The film's showdown when Eboshi's gun makes the Forest Gods neck explode and the body turns into a massive writhing mass of black slime that goes on a rampage in search of its head. Which is kicking around in the metal box it has been put into.
The hands of the blobs of death that bring about instant death while looking for the head of the Forest Spirit, reaching into the forest and killing everything they touched.
The empty-eyed boar "ghosts". They are really hunters with poison darts wearing the skins of the dead boar-gods, but that doesn't make it any better.
Moro's decapitated head slithering across the ground in a last-ditch attempt to get revenge on the woman that shot her.
The very first scene features Nago, a giant boar that is covered by crawling worms and destroying everything in his path. As he dies, we get a close up of his face, as his flesh is melting from his bones. And then there's Okkoto, who is about to suffer the very same fate.
The warriors disguise themselves as boars to trick Okkoto. Something about their movement and lack of eyes. The image of them nuzzling up to Okkoto's side is absolutely horrifying. It's even worse: The disguise works because Okkoto is almost blind. They fool his sense of smell by wearing the skins of his slaugtered tribe.
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.