7x1 - Alvin and the Chipmunks

Theodore encounters a stray kitten that entered through an open window in the house. He and the boys take an instant liking to the kitten, and after some compromising, they name the kitten Cookie Chomper III, and after Dave is cured of his allergy to cats, he comes to like the kitten as well. After Cookie Chomper gets run over, the boys have a hard time dealing with it. Eventually, they get a new pet, a puppy they name Lilly.