Light-hearted cartoons with creepy/scary villains

[The Overlord]

There is a trope noted by TV Tropes where a light-hearted cartoon can feature a particularly creepy or scary villain:

Vile Villain, Saccharine Show - TV Tropes

So you're watching a kids' show taking place in a Sugar Bowl with cute characters and a jolly, lighthearted tone. Then a villainous character is introduced into the plot. But given how inoffensive the work has been up to this point, surely the …

tvtropes.org

Knight of Cerebus - TV Tropes

In order to add more drama to a work which has been, up until that moment, lighthearted and comedic in nature, a villain (or antagonist of some sort) is introduced and is portrayed as a genuine threat, in contrast to the bumbling and comedic …

tvtropes.org

Which light-hearted cartoons do you think have the darkest villains? What do think of putting darker villains in more light-hearted cartoons?

 

[JoeMabbon]

The 2012 Ninja Turtles is much sillier than it’s predecessor while also having a love of body horror in its villain’s character designs.

 

[Dr.Pepper]

One that sprang to mind was the evil book in the Care Bears movie. I think she might be the darkest villain in a preschool show (that I can think of). I like it because it adds a sense of legitimate threat.

 

[pacman000]

Possibly Mewtwo from Pokémon, The First Movie. Tho I’m not sure the series was 100% lighthearted, his backstory & actions in the story proper were very dark.

 

[JoeMabbon]

Coco's primary stakes are family drama for most of the first two acts. The Land of the Dead is a bright, happy wonderland until we find out you can still die in the afterlife. And then we find out Ernesto murdered Hector to steal his songs and is willing to kill again to prevent the truth from coming out.