The Animagus reversal spell is an untransfiguration that returns an Animagus back into its human form. It manifests as a bright blue light and may need to be performed by more than one wizard. If performed on a non-animagus, the spell will have no effect and will not harm the animal. This spell was used in the spring of 1994 by Sirius Black and Remus Lupin to reveal Ronald Weasley's pet rat Scabbers as Peter Pettigrew.