What Do You Do When Your House is a Zoo? by John Kelly (Author), Steph Laberis (Illustrator)

Oscar is SO excited, because his parents have finally said he can have a pet! But he doesn't have any idea what kind to get. So he puts an ad in the newspaper in the hopes that the perfect pet will come to live with him. But soon, too many animals show up at his house, and it's CHAOS!