Disney is infamous as an entity that takes already-existing media and makes "new" copyright-protected "instances" of that pre-existing media.

Examples: Alice in Wonderland, Cinderella. The Disney version of 'Alice' is a very weird hodge-podge of both the 'Alice' books with extra stuff thrown in. Throw in a few mouse-footmen and the story is sufficiently different from the traditional Cinderella.

Being 'sufficiently different', these Disney derivatives are copyrightable as separate works, whereas a work faithful to the originals might not be.