Flea

• Type: Mundane Creature, Pest, Performance Animal
• Owners: Not applicable in the traditional sense. Known hosts include Fang. Known users include Willy Widdershins.
• Maker: Not applicable.

Fleas are small, flightless insects known in both the Muggle and wizarding worlds. They are parasites that survive by consuming the blood of mammalian or avian hosts. They are typically dark-coloured and have bodies that are flattened sideways, which allows them to move with ease through fur, hair, or feathers.

Fleas do not possess any known inherent magical properties. Their significance in the wizarding world is primarily as common pests, mirroring their status in the non-magical world. However, they can be manipulated with magic. Willy Widdershins, a petty criminal, was known to run a flea circus where he used an Engorgement Charm on the fleas. He claimed they were performing complex acrobatics, but the spectacle was actually the result of the charm causing them to swell dramatically and eventually pop, which he disguised with puffs of smoke.

The history of fleas within the wizarding world is undocumented, as they are considered entirely mundane and unremarkable creatures. They have presumably co-existed with wizards and magical creatures for as long as they have with Muggles and non-magical animals.

Fleas are mentioned on several occasions throughout the series, typically to emphasize a lack of cleanliness, discomfort, or a rundown environment.

• In Harry Potter and the Philosopher's Stone, Draco Malfoy disparagingly refers to Rubeus Hagrid's hut as a “flea-bitten dustbin”.
• In Harry Potter and the Prisoner of Azkaban, Stan Shunpike points out that one of the beds aboard the Knight Bus has fleas, highlighting the haphazard nature of the transport.
• Also in Prisoner of Azkaban, Hermione Granger notes that Hagrid's boarhound, Fang, has fleas.
• In Harry Potter and the Order of the Phoenix, Arthur Weasley reads aloud from the Daily Prophet about Willy Widdershins being fined for his enchanted flea circus, which caused a disturbance in a Muggle town centre.

There is no known supplementary information from J.K. Rowling or other official sources regarding fleas in the wizarding world.