Who was Montmorency in Jerome's Three Men in a Boat? What did the narrator think about him initially? When did he change his opinion of the dog?

Montmorency is the dog in the title of the book. He’s a fox terrier. The narrator describes his appearance and reputation – in his usual exaggerating style -- in Chapter II. Here he says that when Montmorency first moved in with him, he thought the animal was angelic and could do no wrong. His opinion changed when he learned that the dog had killed a dozen chickens and a cat, and that their owners demanded restitution for the losses. He had to drag him, “growling and kicking, by the scruff of his neck, out of a hundred and fourteen street fights.” We get the impression that in spite of his small size and adorable looks, Montmorency is a vicious street dog who is always looking for trouble. As with everything else the narrator writes, we’re not sure whether or not we should believe him. We learn more about the dog in Chapters XIII and XIV, when he has an encounter with an even tougher cat; when he offers a water rat for George’s Irish stew; and when he “argues” with the tea kettle.