Fiendfyre

Type: Curse

Description: Unleashes cursed fire that takes the shape of animals that actively seek out living targets and burn anything in its path, including nearly indestructable substances such as horcruxes. In addition, this fire is made even more dangerous due to the fact that it is extremely difficult to control, and cannot be extinguished with normal or enchanted water.

Seen/Mentioned: Though there are numerous instances when it may have been used, it was only proven to have been used in 1998 by Vincent Crabbe, who was killed by it.