Dr. Foulbrain's Lair is a secret world in the game. It's unlocked after defeating all six worlds.
The world has settings like in Factory Frolics. There are only three returning enemies from three worlds in the game. The final boss is a giant Dr. Foulbrain Head.
- Robot (from Factory Frolics)
- UFO (from Sci-Fi Space)
- Jack-in-the-Box (from Slippery Snowland)
If Crazy Drake defeat the final boss, the Sacred Golden Egg gets recovered, but it gets lost! He's prompting the player to play the whole game again.