In the 70's the fundamentals of animation weren't taught as strictly so you ended up with some animators who did a lot of detail that gets lost in the quick movement.
Speaking of OG My Little Pony and uncomfortableness, has anyone seen those Funko Pops of the Gen 1 ponies? They look like they came from a godless, nightmare realm.
So many 80s cartoons had this bizarre "corruption" transformation fetish going on. Someone getting transformed into a grotesque monster under the villain's mind control. Sometimes it took the form of slime.
He-Man: The evil horde slime pit
MLP: this clip, in addition to another plot arc where 3 of the ponies get turned into evil dragons for the villain
The Spiral Zone: the entire show
Inhumanoids: Decompose's zombification
Teddie Ruxpin: an episode where the soldier dude drinks some potion that was spiked with steroids, turns him into a rampaging evil robot knight or something
Visionaries: every third episode seemed to be about the main villain's staff demon sucking the life out of people and turning them into feeble old men
Captain Planet: the drug episode
Smurfs/Transformers: the purple gnat and red spores episodes, although those were more zombie movie homages
There's a bunch of others I'm forgetting. It was just some oddly specific fetish that was universal for some reason.
With Teddy Ruxpin, it was just some Grunge dude giving said character an accidental overdose and making him totally metal. It's the sort of low-stakes story that meshes with "main character bonds with handsy sidekick and this old dude who's into gadgets, SHUT UP ASSHOLE HE'S NOT A BEAR".