Gamp

Gamp is (possibly) the wizard or witch who formulated Gamp's Law of Elemental Transfiguration. Alternatively, it may have been named after him or her by someone else. Gamp must have been good at Transfiguration to invent such a theorem.

Behind the scenes

 * Gamp shares a surname with Hesper Gamp, a witch who married Sirius Black II.

Appearances

 * Harry Potter and the Deathly Hallows