| Villain | Episode | Season |
| Netty Crabbe (the Specter of Ebenezer Crabbe) | |
| The Stone Creature and the Ghost of Katazuma | |
| The Gator Ghoul | |
| The 10,000 Volt Ghost | |
| The Headless Horseman | |
| Merlin and the Black Knight | |
| The Ghost of Dr. Coffin | |
| The No-Face Zombie and the Gorilla | |
| Mamba Wamba, the Mamba Zombie, Zombie Lila | |
| The Steam Demon | |
| Tamooka the Flying Ghost Bull, the Medicine Man Ghost | |
| The Demon Shark | |
| The Ghost of Captain Piscado, the Octopus Monster, the Kelp Monster | |
| The Ramblin' Ghost | |
| The Vanilla, Chocolate, and Strawberry Phantoms | |
| The Ghosts of Benedict Arnold, William Demont, and John Andre | |
| The Viking Ghosts of Viking Lake | |
| The Great Skull Island Vampire | |
| The Pterodactyl Ghost | |
| The Ghost of Milo Booth | |
| | Villain | Episode | Season |
| The Phantom Racer | |
| The Ghost of the Witch McCoy and the Zombie | |
| The Future Shocker | |
| The Creepy Heap from the Deep, the Ghost of Captain Clemens | |
| The Willawaw and the Owlmen | |
| The Skeleton Men of Diablos Island and the UFO | |
| The Snowbeast | |
| Melissa Wilcox, the Ghost Witch of Salem | |
| The Tar Monster | |
| The Ghost of Finnyan McDuff and the Loch Ness Monster | |
| Old Ironface | |
| Jaguaro | |
| The Cat Creature | |
| The Mantis Creature of Vulture's Claw | |
| The Disc Demon | |
| The Moon Monster | |
| The Ghostly Gondolier | |
| The Ghost of General Juan Carlos | |
| Anthos the Warlock | |
| The Beast of Bottomless Lake | |
|