Penelope Rex might finally have bitten off more than she can chew-a pet saber tooth tiger!-in this companion to the #1 New York Times bestselling We Don't Eat Our Classmates by Ryan T. Higgins. Most kids have dogs and cats and fish and guinea pigs. Penelope Rex has Mittens. Penelope wasn't sure she even wanted a pet when Mittens came into her life. But now that he's here, she is determined to make the best of it. Pets, however-especially ones that...