Chou Chou

Chou Chou is a supporting, Anime-exclusive character in the series. He is close in particular with Gavroche and Cosette, after the two take him in as a puppy in episode 3. His breed is never disclosed, but he is most likely a mutt, though he does bear resemblance to the Hungarian Kuvasz, or the Pyrenean Mountain Dog of Spain and France.

Personality
Chou Chou is a very playful, very loyal dog. He is constantly at Gavroche and Cosette’s sides, and is willing to defend them at any cost. Chou Chou also becomes a helpful figure to Pressoir and Jurges when Gavroche "adopts" the two as his younger brothers.

Background/Role in the Story
Chou Chou discovered Cosette and Gavroche one day in a field of flowers. Despite how they tried to shun him away, as the Thénardiers would scold them for bringing an animal home, he followed them home and, after almost getting run over by a cart, began to stay with the two. Cosette stayed with him during his first night outside the inn, and defended him the next morning when Madame Thénardier tried to kill him for destroying her clothes and sheets. Cosette took the beating in his place, and Chou Chou tried to lick her out of unconsciousness.

Time passed and Chou Chou grew into a large animal, large enough for Cosette to ride him through the streets. When Gavroche was sent to work for and live under the care of the blacksmith, Cosette told him to go with Gavroche to take care of him. After hesitating, he followed the boy. When Jean Valjean took Cosette away from the Thénardiers, Cosette and Gavroche, along with Chou Chou reunited before the duo departed, and Cosette asked her childhood friends to come with her. Gavroche, however, declined the offer, claiming that the blacksmith's family was nice to him and that they would be sad if he left. After hugging her "family" goodbye, Cosette left, but promised to write them very soon.

After the second time skip, Chou Chou had remained with Gavroche and sets off with him after he decides to go to Paris. While in Paris, he helps Gavroche steal food and live on the streets, and even saves Gavroche's life at the barricade.

At the end of the series, he is seen waiting for Gavroche, Pressoir, and Jurges outside the schoolhouse. It is more than likely that he stayed with his master throughout the rest of his life.