- Hawkodile being turned into a monster during the pilot.
- The plot of "Bugging Out" might make viewers who have arachnophobia uneasy.
- The part in "Too Many Unikitties", where Unikitty's Happy Horn'd friends go absolutely insane, just for Unikitty disrupting their fun, because Dr. Fox's reactor was melting down.
- The wish coins in "Wishing Well" were pretty much going to kill everyone. One person wanted to fly? She gets thrown off a bridge to drown. Dr. Fox wanted to go to outer space? She gets tied on the OUTSIDE of the rocket ship.note Hawkodile wanted some sparring partners? He nearly gets crushed by the coins that formed them. Someone wanted to find pirates' treasure? The coins make it pretty clear they were planning to trap them at the bottom of the ocean.
- The results of Dr Fox's story in "Scary Tales" is really traumatizing. It involves her being hunted down and eventually devoured by a candy monster, all while documented. Before her story ends, it reveals that she somehow fused with the monster and devours her own arm!
- Fee Bee seems to be a little too addicted to her flowers. In "Volcano", after the gang takes her most beloved flower, she follows them on their journey without them knowing, and when they arrive in a dark and scary forest, she comes in looking like she just escaped from the insane asylum and guides them into a scary cave, all for a fucking flower. The climax even shows she's willing to let the whole Unikingdom die by lava if it just means getting her ''precious'' flower back.
- The episode itself ends on a dark note, with the Volcano sneezing due to the flower's pollen, and his lava completely covering the Unikingdom anyway. It doesnt help that Unikitty and Feebee are on the rim of the volcano when this happens.
- Some of the endings of certain episodes in general can be seen as this.
- In "Lab Cat", a fragment of Tasty's Comet crashes into the siblings' already crashed escape pod, and the two, along with Dr. Fox, begin cheering as more fragments crash into the Unikingdom in the background. The last split second is a meteor falling onto the trio.
- "Unikitty News" ends with Dr. Fox's black hole swallowing everything (and everyone) into it, before ending on a technical difficulties screen.
- "No Day Like Snow Day" ends with Master Frown in a whopper of an And I Must Scream situation, floating out into the cold ocean, stuck inside of a snowman, all while Unikitty and her friends mistake his screaming for a call.
- "Beach Daze" ends with the gang being carried off by crabs to be pinched, all because, to quote Crabatar, "You can never trust a crab."
- "Tooth Trouble", with the Tooth Fairy taking the gang's teeth for what they did in the episode.
- "Election Day", has Unikitty and Frown's votes tie up, Richard stating that if the votes tie, whoever voted first will be princess, who turns out to be Ted Butter. While everyone bows to him at first, the episode ends with a shot of a duck-tator ruled kingdom, complete with leafless trees, and stormy skies, Unikitty and her friends' fates not determined.
- The Disney Acid Sequence in "No Sleep Sleepover" has the Sandman chase down Unikitty and her friends in a colored-outline sequence, ending with the siblings being buried alive in a giant hourglass. The terror is only reduced slightly by the reveal that it was All Just a Dream.
Nightmare Fuel / Unikitty!