Theories of Transubstantial Transfiguration is a book, a copy of which resides in the library of Hogwarts School of Witchcraft and Wizardry. The librarian, Irma Pince, added unusual jinxes to the copy, so that when Albus Dumbledore absent-mindedly doodled on a copy, it began to beat him around the head.

Appearances

• Quidditch Through the Ages