|Diet||Oxygen, hydrogen, other combustibles|
|Behind the Scenes|
|Created by||J. K. Rowling|
|Designed by||J. K. Rowling|
Fiendfyre are bewitched flames infused with dark magic, capable of seeking out targets despite not being sentient.
It is an immensely powerful fire that cannot be extinguished by normal or enchanted water, being very difficult for the caster to control, flowing from their wand in a continuous stream of flame. If the caster flicks their wand when the stream of fire is still running from it, a flames will shoot off it and become a flaming animal.
When cast, the fire appears with a roaring, billowing noise and gives its victims only a split-second's warning before attacking, quickly consuming anything in the vicinity of its caster. The flames are of abnormally large size and take the shape of fiery monsters and beasts such as snakes, dragons, eagles and chimaeras, constantly mutating into other beasts as well as powerful, formless flames that destroy all things flammable around it. The fire possesses an instinct of its own, a continuous (though far from latent) desire to burn anything it can. It will pursue any nearby lifeforms and anything that it can destroy, and is capable of incinerating anything through mere contact.
Inexperienced casters will be able to conjure the flames but will have virtually no control over the curse once it has been unleashed, thereby making the fire a deadly backfire. More experienced casters, such as Voldemort, may control the flaming beasts they create, even condensing it into a single, colossal animal of their desire. There is also a charm to cease the flames as well as one to disperse them, but Vincent Crabbe never paid attention in class long enough to learn it, a fact that cost him his life. It is also possible that the fire may eventually burn off on its own, if it is unable to consume enough material to sustain it, and if so, the ash left behind may become ashwinders.