Mrs Norris

Mrs Norris is the scrawny, dust-coloured cat belonging to Argus Filch, the embittered caretaker of Hogwarts, in J. K. Rowling's Harry Potter novels. Described with bulging, lamp-like yellow eyes and a skeletal frame, she is introduced early in Philosopher's Stone as a creature students learn to dread on sight, because where she goes Filch inevitably follows.

Her function in the school is essentially that of an informer. She patrols the corridors alone, and the books suggest an unusually close bond with her master — spot a rule being broken and she will fetch Filch to the scene, apparently able to communicate the offence to him. Students accordingly treat her as an extension of the caretaker rather than as a pet, and a good deal of the series' low-level tension about being caught out of bounds after dark hangs on whether Mrs Norris is nearby.

She also has one moment of genuine plot significance. On Hallowe'en in Chamber of Secrets she becomes the basilisk's first victim, discovered hanging stiff by her tail beneath a message daubed on the wall. Because she saw the creature only as a reflection in a puddle of water, she is Petrified rather than killed, and is restored later that year by the Mandrake Restorative Draught brewed under Professor Sprout. Her attack is the incident that sets the whole mystery of the Chamber in motion, and Filch's grief over it is one of the few glimpses of vulnerability the character is given.

The name is a literary joke. Rowling took it from Mansfield Park by Jane Austen, one of her favourite authors, where Mrs Norris is an interfering, unpleasant aunt who lurks in the background of the household making everyone's life a little worse — a description that transfers to the cat almost without adjustment.

In the films Mrs Norris was played by Maine Coons, among them cats named Maximus, Alanis and Cornilus, supplemented by animatronic doubles for shots the live animals could not manage. The breed's shaggy coat and heavy build gave the screen version a more imposing look than the bony creature of the books, and helped make her one of the most instantly recognisable animals in the series.