Demon

In the wizarding world, the term Demon is not an official Ministry of Magic magizoological classification. Instead, it is a descriptor used for exceptionally malevolent, destructive, and powerful entities, which can include both magical constructs and, colloquially, certain magical beasts. The word itself does not appear in the original seven novels but has been established in supplementary canonical materials to describe manifestations of Dark Magic and particularly dangerous creatures.

The term “demon” has been applied in at least two distinct contexts within the wider Harry Potter universe.

Fiendfyre is a highly advanced and immensely destructive curse that produces sentient, cursed fire. This fire actively seeks out and incinerates living beings and can destroy even famously resilient magical objects, including Horcruxes. The flames are known to mutate and take the form of gigantic fiery beasts. While the primary canon describes these forms as including serpents, Chimaeras, and dragons, supplementary material confirms that the cursed fire can also form itself into the shape of demons (Pottermore). This suggests that the nature of a “demon,” in this context, is a being of pure malevolent magical energy given form and a destructive purpose.

The term has also been used as a colloquialism to describe magical beasts of extreme power and danger. The most notable example is the Nundu, a gigantic leopard-like beast native to Africa. The Nundu's breath is so toxic that it can spread disease capable of annihilating entire villages. Due to its lethality and the fact that it has never been subdued by fewer than one hundred skilled wizards working together, it is considered one of the most dangerous creatures in existence. In the film Fantastic Beasts: The Crimes of Grindelwald, the character Yusuf Kama refers to a Nundu he is hunting as a “demon,” reflecting the immense fear and peril associated with the creature (film).

The use of the word “demon” in the wizarding world mirrors its use in the Muggle world: it is a term of dread rather than a precise scientific label. It is applied to phenomena and beings that represent a profound and often intelligent evil, operating beyond the normal scope of magical creatures catalogued by the Department for the Regulation and Control of Magical Creatures. Its application to both the elemental constructs of Fiendfyre and a living beast like the Nundu highlights that the wizarding community defines a “demon” by its capacity for overwhelming destruction and its seemingly malevolent nature.

• The word “demon” is never used in the original seven *Harry Potter* novels by J.K. Rowling. All references to demons come from secondary canonical sources.
• The description of Fiendfyre being able to take the form of demons is found on the Wizarding World website (formerly Pottermore).
• The use of “demon” to refer to a Nundu is from the screenplay and dialogue of the film Fantastic Beasts: The Crimes of Grindelwald.