Fiendfyre, also known as cursed fire, is a type of fire made with Dark Magic. It is so powerful that a Fiendfyre cannot be put out by Aguamenti, the water spell, or any other type of water spell. Fiendfyre is even difficult for the caster to control. A Fiendfyre's flames are of abnormal size and can take the shape of fire-breathing monsters and beasts such as serpents, chimaeras, dragons, and raptors that continuously start mutating constantly. It is currently unknown if there is a counter-curse for Fiendfyre, and Aguamenti merely evaporates before even touching it. Inexperienced casters can easily conjure Fiendfyre, but will have no control over the flames once they are unleashed, which would make a Fiendfyre an exceptionally deadly backfire. But, an experienced Dark Wizard such as Lord Voldemort would be able to easily control the flames and manipulate it to a greater and deadlier effect.