Azkaban

Ron: I'm warning you, Hermione! Keep that bloody beast of yours away from Scabbers or I'll turn it into a tea cozy. Hermione: He's a cat, Ronald! What do you expect? It's in his nature. Harry reaches the bottom of the stairs Ron: A cat! Is that what they told you? Looks more like a pig with hair if you ask me. Hermione: That's rich coming from the owner of that smelly old shoe brush. Hermione pets Crookshanks It's all right, Crookshanks. You just ignore the mean little boy...