Mutatis is a magical spell.
A magical spell which allows the caster to transfigure an object into a variation of itself, Mutatis is, as befits its name, itself highly mutable, seemingly limited only by the power of the caster's imagination. Relying on hand gestures for its casting, it nonetheless appears to be such a powerful spell that even the greatest of sorcerers — even wizards and witches who need no wand or artifact to practice magic — need the Sorcerer's Hat or some other object of immense power to successfully use it.
The spell was used by Yen Sid in 1940 to turn a bat-like cloud of smoke which he had previously conjured into one resembling a colorful butterfly. Observing this, his then-apprentice, Mickey Mouse, learned the spell and used it moments later to bring a broom to life, giving it arms and setting it to work fetching water for him.