Since the conception of the first Kingdom Hearts, Tetsuya Nomura had wanted to include a world based on Fantasia, but was unable to and ended up only including Chernabog as a boss in End of the World, though in a battlefield very similar to the Night on Bald Mountain segment.
Kingdom Hearts 3D: Dream Drop Distance
Mickey is seen here, during his apprenticeship under Yen Sid. During both Sora and Riku's visits, a Spelllican Dream Eater has put him into a dream; one horrific nightmare about the brooms flooding the room with water and the other with him mastering the magic of Yen Sid's hat.
Sora and Riku go to Pastoral Symphony and Nutcracker Suite respectively to find the music to break the spell on Mickey caused by the sheets of music in the room. Successful, they end up fighting the Spellican to break Mickey free of its control. Once done, Mickey thanks both of the heroes and realizes the error of his mistakes. The Keyhole for this world opens in the Sorceror's Loft after Mickey leaves.