The Homorphus Charm was described by Professor Gilderoy Lockhart as what he used to cure the Wagga Wagga Werewolf. He described the spell as being "immensely complex." He later admitted to having stolen the credit from an Armenian warlock.
As Lockhart is known for providing phony spells, and given that there is no known cure for Lycanthropy, it is possible that this spell does not truly exist, or has a different effect than Lockhart described (possibly just temporarily forcing a transformed person back into human shape, rather than preventing the change).
Homorphus is a combination of the Latin Homo meaning 'man' and the Greek morphe- meaning 'shape' or 'form'.
Behind the scenes
- Although this spell is described as a charm, its effects seem closer to Transfiguration.
- It is possible this spell was used to force Peter Pettigrew out of his Animagus form in 1994.