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Nightmare Fuel: Are You Afraid of the Dark?
Wanna go for a swim?
For a children's series that had to go light on the gore, Are You Afraid Of The Dark? had more than a few legitimate scares that hold up to this day.
Please add only examples, not your own experiences.
The intro. This troper was scared to death of it as a little kid.
The episode where the kids are trapped in a dollhouse and are slowly turning into porcelain dolls, one of whom is already so far gone that her hand falls off when she tries to help move a heavy piece of furniture.
Especially how it was delivered. The protagonist asks the girl to help her move the furniture. The girl doesn't even change her facial expression, but simply pulls her hand out of the sleeve.
The ending of "The Tale of the Chameleons" when is revealed that Sharon didn't choose the right Janice. Yep that's right, she turned her helpless best friend back into a chameleon and threw her into a well to drown. And her parents and loved ones have no idea. And meanwhile the imposter Janice remains undetected and is probably planning to do the same to Sharon.
The Nosferatu episode where none other then Orlok himself came out of the movie and started coming after the kids.
Every episode with vampires, "The Tale of the Night Shift" for one.
"There's no use in running. I'm far too good a hunter!"
"And isn't the hospital a great place for it? It's like...a candy store."
One of the most disturbing quotes in known history comes from the vampire after he's caught the main character:
"I should drop you and then lick up what's left!"
"The Tale of Dead Man's Float". Just like Tim Curry's portrayal of Pennywise, this episode will make you afraid of shower drains, not to mention swimming in the deep end of the public pool. It's considered one of the scariest episodes of the series.
"The Tale of the Ghastly Grinner", with the idea that something evil can reduce absolutely anyone to a giggling, drooling imbecile simply by staring into your eyes.
Simply put, the guy was basically The Joker, except with hypnotism rather than gasses.
The Tale of the Quicksilver opens with a girl trying to summon a demon to the real world so she can get rid of it. Not only does she fail at it, but she ends up burning her room and killing herself. Later, it's revealed that the girl who died was a living girl's twin, and the house that her new friend moved into was the one she lived in until her sister died.
The Tale of Old Man Corcoran. You never find out how or why the leader of the group of Hide-And-Seekers keeps gathering more and more kids to play these games, yet once the old grave digger explains that all those kids have been dead for years, the Fridge Horror comes in buckets. First, the girl who tries to keep those boys out of the group was just trying to make sure they didn't end up like her: a ghostly participant eternally bound to a game of Hide And Seek in the graveyard. Second, the leader of the group who was trying to get the two boys to come into his open grave was likely just going to somehow kill them and bind them to said eternal game of Hide And Seek. Third, that's why you never see the Hide And Seek group ever change their clothes during the new day, and why they are always colored in blues and whites during the night sequences. They are all dead.
Even worse? When the leader called out everyone to start their game all over, the kids each came out from hiding behind (possibly their own) graves.
On the bright side, it was a nice aversion to the horror movie cliché of the token black guy in the group being the first one to die.
In "The Tale of the Twisted Claw," one non-supernatural scary moment is when the teenagers in creepy plain white masks surround the two kids who are trick-or-treating and circle them, teasing and threatening them. The ep also gives us a nice Nothing Is Scarier moment when the kid wishes for his grandfather to come, before remembering he's dead. And then they see his car...
The aliens in "The Tale of the Thirteenth Floor". Their faces are featureless, stone-colored things with no eyes, mouth or anything. This on its own would be creepy enough, but what really sells it is the way they move. The director had the rather brilliant idea that a creature with no face would have to communicate entirely through body language, and directed the actors playing them accordingly. As a result they all move in a very twisted, puppet-like manner because of all the information they need to convey to each other through their gestures. The way they're all wiggling their fingers at the end is especially bizarre. It might look silly on anything else, but considering how creepy the things are to begin with...
That god damn Crimson Clown that would not go away until the younger brother vowed to be good.
"The Tale of the Many Faces" - what the girls look like when Madame steals their faces. And they're forced to wear masks to cover themselves up, which is arguably creepier.
In "The Tale of the Dream Girl", Johnny hears Donna calling for her. He walked around the bowling alley to find her, but she disappeared. As he was leaving, we cut to a bowling ball rolling, and the sound of it becomes very loud like an approaching train. The ball hits the pins, and suddenly Johnny hears a girl screaming, he covers his ears and turns back to see a female bowler screamed because she made a strike. We learn that both Johnny and Donna were run over by a train.
"The Tale of the Phone Police" While the episode is pretty mundane compared to the other examples, there are still nightmare inducing factors. Imagine a secret origination that can take you away regardless of Law and Human Rights, erase all record of your existence and even go as far as to have members of your own family not remember you. To make matters worse you have to spend eternity inside a jail cell with nothing but a phone to call the outside world. And these guys do all that to people who abuse the phone (I.E. Prank Calls.) Makes excellent Paranoia Fuel on top of that.