When you look back on your childhood, what (hopefully) sticks out for you are the moments of boundless enthusiasm, how you used to get so much more excited about sleepovers, and that, at the drop of a hat, you could convince yourself that the floor was lava and fight with every ounce of your being to not touch it.
But it's also easy to forget the intense bouts of fear that came with being a little kid. Maybe it's because you valued your life that much more as a child, or it could be that you felt really small (because you physically were smaller) so everything seemed that much more intimidating. In any case, I don't recall ever being as freaked out by things as much as I did when I was younger.
And it's not like our favorite TV shows did much to help quell those fears, either. At least, not with these scenes. People in an AskReddit posted dark moments from kids' shows that still haunt them to this day.
That one episode of Pingu where he has a nightmare and is chased by that god-awful seal/walrus and his bed is all animated and everything.
The Magic Schoolbus
That episode of The Magic Schoolbus where Arnold took his helmet off on Pluto to prove a point to his obnoxious cousin. Literally watched Arnold commit what should have been suicide in front of his teacher and classmates.
Star Wars: The Clone Wars
Bad guys land ship, a bunch of kids from local village gather around excited about the supposed supply ship.
Bad guy 1: Brother, what are we doing this far out in the galaxy? The Jedi won't be here.
Bad guy 2: There's only one way to gain the attention of the Jedi at wartime. Lightsaber ignition camera pans to the children. Mass slaughter of the innocent, without compromise or mercy.
Then they show the message he sends to the Jedi, including him decapitating like five people. When the Jedi get there, the whole village is on fire and nobody is there.
The Danny Phantom episode where he goes to the future and learns that he killed his parents with his powers accidentally, and [goes] insane and becomes the biggest threat to the world. That was super dark.
Fairly Odd Parents
That one episode of Fairly Odd Parents where he sees that everyone's life would be better off if he had never been born.
The Teen Titans episode where Robin keeps seeing Slade and no one else can see him.
For years I had these vague memories of an episode of Arthur about a fire at the school. For whatever reason I never actually googled it and just assumed that I either made up that episode in my head or was misremembering it. Well I found out on Reddit not all that long ago, that not only was that a real episode, but it was written in response to 9/11.
Winnie The Pooh
That awful f--king hefalumps and woozles (or whatever the f--k they are) scene in Winnie the Pooh. Scared the literal sh-t out of me as a child.
Over The Garden Wall
When the woodsman discovers he's been chopping trees made from dead children.
Tom and Jerry
There's a Tom and Jerry episode set in revolutionist France and Tom f--ks up, meaning he gets the guillotine. You don't see his head cut off, but you see the top of the guillotine fall, followed by Jerry and his sidekick having a moment for Tom. It's a definitive moment of mortality for a popular cartoon character and it gave me the creeps back in the day.
Where Superman was controlled into thinking he had a family in Krypton, and the one where Batman had to kill a kid.
The Spongebob episode when squidward gets a toe nail ripped off.
Avatar: The Last Airbender
The one episode of Avatar: The Last Airbender where they find that ancient library that was buried in the sand for hundreds of years and they go in and there's that giant owl spirit with the most unsettlingly monotone voice I've ever heard.
Courage the Cowardly Dog
Literally any episode from Courage the Cowardly the Dog. That show was unsettling.
The episode of Invader Zim when Zim harvested the organs of his classmates. F--ked me up for a while.
The Marvelous Misadventures of Flapjack
Flapjack is my to-go on disturbing children shows.
If that's not enough, have this compilation of them. Most are just... weird?
My Life As A Teenage Robot
Season 1 episode 7 Return of the Raggedy Android from My Life as a Teenage Robot. Available on Hulu.
The robot gets a fake skin to make her look more real. However it gains sentience and is terrifying!!! My daughter loves that show and watches horror movies like Nightmare on Elm Street with no problems. That sh-t terrified her and she specifically calls out not wanting to watch that episode still, 8 months later.
Batman: Return Of The Joker
There was the Batman Beyond movie where the Joker kidnaps Robin, tortures him into becoming Joker Jr, and then gets shot to death by Joker-Robin with his last words being "That's not funny..."
It was so dark they had to animate a completely different version of the scene for TV airings.
The Adventure Time episode where LSP murders her boyfriend because she thinks he's cheating on her by going to a business meeting, then erases her memory of him.
While we're at it, I'm going to add the intros to Finding Nemo and Up. Man kids movies can be depressing.