Crookshanks

Crookshanks is a fictional ginger half-Kneazle cat owned by Hermione Granger in the Harry Potter series by J.K. Rowling. He is introduced in Harry Potter and the Prisoner of Azkaban (1999), bought by Hermione from the Magical Menagerie in Diagon Alley where, according to the shopkeeper, he had been waiting for the right owner "for ages." His distinctive squashed face, bushy tail and bandy legs are described in the books as making him "extremely ugly."

His Kneazle ancestry — Kneazles being magical felines noted for their intelligence and their ability to detect untrustworthy people — is significant to the plot of Prisoner of Azkaban, where he correctly identifies the rat Scabbers as the disguised wizard Peter Pettigrew long before the human characters do. He also recognises that Sirius Black, the man everyone else fears, is innocent. His persistent attacks on Scabbers, dismissed by Ron as bad behaviour, are in fact the cat trying to unmask a fraud.

In the film adaptations, Crookshanks was portrayed primarily by a red Persian cat named Crackerjack, with several Persian and British Shorthair doubles handling action shots. His characterisation as wise, fiercely loyal, and capable of judgement well beyond an ordinary cat made him a beloved figure in the series. Crookshanks remains one of the most recognisable fictional cats in modern literature.