Hell Is That Noise/Western Animation

""Naaaaaaaaaaaaughtyyyyyyyyyy...""
 * Courage the Cowardly Dog loves this trope.
 * The repeating "It's Doc Gerbil's World!" song that sounds like the demented cosmetics themed version of "It's A Small World After All" during the boat road in "Human Habitrail" is either this or incredibly annoying.
 * Any moment where the sound effects and dialog are cut and instead is played a One-Woman Wail or Ominous Latin Chanting. Any of the episodes that get that treatment quickly become genuinely disturbing.
 * The music in the "Freaky Fred" episode. Accompanied with Fred's cheerful rhyming narration throughout the entire episode. The most disturbing scene is when Fred and Courage are locked in the bathroom together and Fred shaves Courage with a manic grin on his face while a haunting chorus of "la-las" starts to accompany the already eerie music.


 * "RETUUURN THE SLAAAB!"
 * "You're not perfect"
 * Whenever Katz made an appearance. You could tell a few seconds before he was actually shown, by the creepy beat that suddenly started playing. And it kept playing. Until it could cause shuddering years later.
 * Played for laughs in a Rocko's Modern Life episode, where the gang is shown walking in a forest and they suddenly heard a noise, freak out, and shout "What was that?!" Filbert calmly walks past them saying, "Oh, just a twig snapping", which turns out to be true.
 * Avatar: The Last Airbender
 * Every single time the camera focuses on Azula's face, a Scare Chord plays. Though instead of the standard blaring piano keys, she gets a distinct bell-like sound that is a lot quieter and means she's up to something sneaky.
 * It seems like a modified gamelan... which would sound pretty weird to western ears. But even if you're used to the noise, this one is a little off.
 * The tortured cello that plays during her Villainous Breakdown, right before she slices her bangs off.
 * The crazy noises that Azula made when she finally broke down and cried.
 * "There's no war in Ba Sing Se" and "The Earth King has invited you to Lake Laogai."
 * That bird that freaked out the Gaang in "The Swamp." Appropriately, it's called the Screeching Dodo. It's pretty harmless, though.
 * Oh god the music they play when you realize there's no one else in the room after Azula hallucinates that she's talking to her mother in a mirror. It's this wrenching, dying sounding chord that just makes you think "that's it, she just broke".
 * "WESSST!" from The Marvelous Misadventures of Flapjack.
 * As well as the Skymaid's usage of the word "Yes" from the episode "Gone Wishin".
 * "CLOOOOOOOOOSED." Don't tell me you didn't wet your pants.
 * She's heeeeeeeeere.
 * Hey Arnold: One particular nightmarish segment in which Arnold's Grandpa is an old corpse that's still alive has him saying to Arnold "What did I tell ya, Short Man?" He then proceeds to laugh in a really creepy way while some ominous music plays before his jaw breaks with a loud "CRACK!" and falls off his skull.
 * The Maxx: The animated series featured a flashback story from Mr. Gone's past and Julie's childhood, involving a dying bunny in a box and the scratching noises it made with its good leg.
 * The lovely noises start at around 4:20.
 * Spongebob SquarePants:
 * The loud buzzing sound that came with the live-action deerfly close-ups in the episode "Wormy".
 * In "SB-129", Squidward travels through time and ends up in a blank white void. He remarks to himself that he can finally be alone... which is when the word manifests itself as a colorful caption. Then a series of disembodied voices start saying the word "alone", accompanied by more colorful representations of the word, until Squidward finally snaps and tries to get out. Just those calm, echoing voices that repeat the word "alone".
 * The Ominous Music Box Tune that is heard during Patrick's Break the Cutie moment in the episode"Nature Pants": "If I can't have you as a friend, I'm gonna make you a trophy!"
 * The song "Ghost Child" from "Scaredy Pants".
 * The music that plays in this video. It's the 'generic' Spongebob creepy music.
 * It also plays during the sequence in "Squid's Day Off" where we see Squidward going insane and blocking off his door to his house to prevent him from going back to the Krusty Krab to check up on Spongebob.
 * The "I DON'T NEED IT" scene in "Tea at the Treedome". Spongebob's dried up face is zoomed in on in terrifying detail, complete with an unnerving heartbeat sound.
 * In-universe example with the squeaky boots and Mr. Krabs.
 * Teen Titans used this in form of a heart beating with the villain Kardiak, a giant heart with metal tentacles that eats children.
 * The Ren and Stimpy Show owed most of its Nightmare Fuel to this trope. This saw theme is a good example. Practically every episode has some of this, particularly whenever Ren went Ax Crazy, which was often.
 * Unsurprisingly, Invader Zim
 * "Dark Harvest" gives us the sound of a pigeon cooing - warning you that Zim is nearby and is going to try and steal your organs, replacing them with something else... In that same episode there's also the music that plays when Dib goes looking for Torque after losing sight of him.
 * The credits music and the theme music (especially that growling/screaming noise at the end when the title "Invader Zim" comes up)
 * In "Bad, Bad Rubber Piggy", you can hear what sounds like a ticking clock in the background starting after Dib is hurt for the second time and lasting up until he flatlines.
 * The Joker's laugh on Batman the Animated Series can be this from time to time.
 * Hearing it from The Joker himself isn't the only thing that makes it qualify for this trope. On multiple occasions, you have him using his trademark smile toxin on unexpecting individuals, causing them to uncontrollably break out into that same laughing madness.
 * Powerpuff Girls: Him's voice. It ranges from a cheerful lisp to a raging roar to an insidious whisper, with a constant creepy reverb throughout.
 * The "Graffiti" Klasky-Csupo logo.
 * Rugrats:
 * The voice of the monster under Chuckie's bed in the episode "Under Chuckie's Bed".
 * The horrible creaking noise of Angelica's chair in the episode "What The Big People Do".
 * The first Halloween episode had some pretty creepy background music.
 * The ending credits music from the episode "Mega Diaper Babies".
 * The music that plays in the background when Not!Tommy and Not!Stu speak, also the voices of Not!Tommy and Not!Stu.
 * Roughnecks Starship Trooper Chronicles does this in one episode, in which Rico hears a mysterious and creepy grinding sound while in a recovery vat after sustaining heavy injuries in battle, a sound no one else can hear. His crew and the medical team working on him all worry about his mental health, until bugs emerge in the base and they realize he could hear them tunneling in.
 * Discord from My Little Pony Friendship Is Magic gets this with his Evil Laugh at times. His default one is appropriately evil, but he has a far more menacing and sinister sounding one he lets off whenever he's not directly onscreen. It will definitly give you nightmares...
 * And just listen to the Creepy Circus Music playing during Pinkie Pie's "party" in "Party Of One".
 * The squawking the cockatrice makes sounds like a cross between a crow cowling and a chainsaw starting up.
 * Adventure Time:
 * IT'S THE ONLY WAY! OHOHOHOHOHO!
 * Also YMMV as a Most Annoying Sound, Ludwig Von Koopa's laugh. OooOooohOooh!
 * Amon's voice in The Legend of Korra. Being voiced by Steve Blum helps. His Leitmotif probably also counts.
 * As Tarrlok is bloodbending Korra, you can actually hear the fluids inside her swishing around.