Matagot

The Matagot is a magical beast that resembles a large, black cat in appearance.^[1]

Description

In France, they are used by the French Ministry of Magic for handiwork, such as handling the correspondence and security of some departments. Normally, they are harmless, but when provoked, they turn into very ferocious creatures.^[1]

Matagots appear to be resistant to most forms of magic and spells, and can multiply themselves upon being hit with offensive spells, such as the Stunning Spell.^[2]

Upon exiting the wizarding world, Matagots will turn into ordinary black cats.^[2]

Behind the scenes

A Matagot is a spirit in French folklore that tends to take the form of a black cat. While many Matagots are evil in nature, some can be helpful to humans. If a "wealth-bringing" Matagot is allowed to eat and drink first at every meal, it will give its owner a solid gold coin each morning.
The Matagot closely resembles the specially-bred Sphynx breed of domestic cat, known for its lack of coat (fur).
Newt Scamander mentions that they are spirit familiars, which is a subject of much debate and controversy in the fandom. This is because J. K. Rowling has previously stated that "familiars, in the strictest sense, do not exist in the world of Harry Potter",^[3] after years of fans debating whether or not Hedwig was Harry Potter's spirit familiar.
- It is worth noting that the exact phrasing suggests that something one could call a familiar may exist, but nothing that rigidly adheres to the archetype of such a thing.