Mrs Norris was a ‘dust-coloured’ cat with ‘bulging, lamp-like eyes’ and was Argus Filch’s loyal sidekick. As his second-in-command, she would patrol the corridors of Hogwarts looking for rulebreakers and would then lead Filch to the misbehaving students. The two of them appeared to be able to communicate wordlessly and had unshakeable bond.