Filch owned a cat called Mrs Norris, a scrawny, dust-colour creature with bulging, lamp-like eyes just like Filch’s. She patrolled the corridors alone. Break a rule in front of her, put just one toe out of line, and she’d whisk off for Filch, who’d appear, wheezing, two seconds later. Filch knew the secret passageways of the school better than anyone (except perhaps the Weasley twins) and could pop up as suddenly as any of the ghosts. The students all hated him and it was the dearest ambition of many to give Mrs Norris a good kick. scrawny - very thin in a way that is not attractive.