Cats in the Wizarding World

Cats are common domestic animals found in both the Muggle and Wizarding worlds. Alongside toads and owls, they are one of the three types of pets that students are permitted to bring to Hogwarts School of Witchcraft and Wizardry. In wizarding society, cats serve not only as companions but also as familiars, and their form can be adopted by a witch or wizard who is an Animagus. Certain cats in the wizarding world possess magical heritage, most notably part-Kneazle cats, which are known for their exceptional intelligence and ability to detect suspicious individuals.

Cats are a popular choice for a wizarding pet, available for purchase at magical pet shops like the Magical Menagerie in Diagon Alley. Their presence at Hogwarts is commonplace, though they are sometimes seen as less practical for delivering mail than owls. Beyond simple companionship, some cats exhibit a deep, almost psychic connection with their owners. Mrs. Norris, the pet of the Hogwarts caretaker Argus Filch, effectively acts as his deputy, patrolling the corridors and seeming to report student misbehavior directly to him. This connection suggests a magical bond that transcends that of a typical pet. Cats can also act as sentinels; members of the Order of the Phoenix, such as Arabella Figg, used her part-Kneazle cats to keep watch over Harry Potter during his childhood on Privet Drive.

• Crookshanks: The large, ginger, bandy-legged, and bottle-brush-tailed pet of Hermione Granger. Crookshanks is exceptionally intelligent due to being half-Kneazle. He immediately recognized Scabbers the rat as the Animagus Peter Pettigrew and Sirius Black in his dog form, assisting Sirius Black throughout Harry's third year.
• Mrs. Norris: The scrawny, dust-coloured cat belonging to Argus Filch. She has bulging, lamp-like eyes and an uncanny ability to spot students breaking rules. In Harry's second year, she became the first victim of the Basilisk, though she was Petrified rather than killed, as she saw its reflection in a puddle of water.
• Minerva McGonagall's Animagus Form: The Head of Gryffindor is a registered Animagus who can transform into a silver tabby cat at will. This form has distinctive spectacle markings around its eyes, mirroring her own glasses. She uses this form for observation and disguise, notably when watching the Dursley family before leaving Harry Potter on their doorstep.
• Arabella Figg's Cats: Mrs. Figg, a Squib who lives near the Dursleys, is a breeder of part-Kneazles. Her cats include Mr. Tibbles, Snowy, Mr. Paws, and Tufty. Mr. Tibbles was assigned to watch Harry Potter and alerted Mrs. Figg to the Dementor attack in the alleyway near Privet Drive.
• Millicent Bulstrode's Cat: During their second year, Hermione Granger attempted to use a Polyjuice Potion to disguise herself as the Slytherin student Millicent Bulstrode. However, the hair she procured was from Millicent's cat, causing Hermione to partially transform into a cat-human hybrid, complete with fur, a tail, and feline eyes.
• The Weasley Family Cat: The Weasley family is mentioned to own a cat that their old family owl, Errol, sometimes crashes into upon returning from deliveries.

The connection between cats and magic is ancient and multifaceted in the wizarding world.

• Animagus Transformation: The cat is a known form that a witch or wizard can take as an Animagus, as demonstrated by Minerva McGonagall.
• Patronus Charm: A cat is a possible corporeal form for a Patronus. The most prominent example is that of Dolores Umbridge, whose Patronus takes the form of a large, silver cat, which she used to ward off Dementors at the Ministry of Magic. This demonstrates that the ability to produce a Patronus is not necessarily linked to a pure heart.
• Kneazle Hybrids: Cats can be cross-bred with the magical creature known as the Kneazle. The resulting offspring, like Crookshanks, inherit the Kneazle's high intelligence, independent nature, and ability to identify untrustworthy people.
• Potions: Cat hair, while not a standard ingredient, can be used in Polyjuice Potion. However, as it is meant for human-to-human transformation, using an animal part results in a difficult-to-reverse and distressing partial transformation into that animal.

• In interviews, J.K. Rowling has expressed a fondness for cats and has identified herself as a cat person. (J.K. Rowling interview).
• The character of Dolores Umbridge and her affinity for cats and kittens (displayed on her garish decorative plates) was created to illustrate the theme of superficial sweetness masking a corrupt and cruel nature.
• The surname of Mary Cattermole, a Muggle-born witch whom Umbridge cruelly interrogates, is thematically linked to Umbridge's cat Patronus, enhancing the predatory nature of the scene.
• In the film adaptations, both Crookshanks and Mrs. Norris were portrayed by multiple specially trained animal actors. Crookshanks was primarily played by a Persian cat named Crackerjack. (film).