Untransfiguration was a branch of transfiguration magic and a type of counter-spell, which involved returning something to its proper form, reversing the effects of a transfiguration. Untransfiguration was covered in beginner-level spellbooks such as A Beginner's Guide to Transfiguration. Learning untransfiguration was mandatory at Hogwarts School of Witchcraft and Wizardry from 1926 onward. Failure to at least attempt to untranfigure a wrongly-done transfiguration was considered irresponsible.