The Horned King from The Black Cauldron
You have to start the list with an underdog, and to me, The Black Cauldron is Disney’s big underdog.
Why did so few people like or see this movie? It was everything a nerd kid could want. It was (low) high fantasy, and it was incredibly well-done (but vastly under-appreciated). Honestly, one of the things that makes this movie so memorable for me was just how fucking scary the Horned King was. I grew up reading this series of Lloyd Alexander books (that this cartoon was based on) and Disney perfectly brought to life the exact vision I had of this tyrannical, undead-beast.
On top of that, he was not one of those villains who broke out into song. No. He was just a skeleton with horns who was fully intent on bringing an army of undead zombies to life so that they can take over.
If you see a list of Disney villains and this guy isn’t on it, that shit was written by a tourist.