An odd take on friendship in this brightly illustrated but unsatisfying book. Libby's next-door neighbor Matilda turns up frequently to borrow Libby's bike, horn in on Libby's picnic, and ``share'' school supplies. Libby grows tired of lending her a quarter for ice cream every day; when she discovers her favorite socks on Matilda, she takes action. Libby stops taking ice cream money, tells Matilda the bike has a flat tire, and has her picnics indoors, but she can't escape when Matilda is made her partner for a class project. Feigning illness, Libby goes home to brood. Matilda comes over with a homemade get-well card and cupcakes, but also wearing Libby's hat—reform is far away. The gouache and pen-and-ink illustrations are lively, but Matilda is such an obnoxious character that one wonders why some convenient adult doesn't just smack her one and get her to mend her ways, or why Libby doesn't light into her—a couple of cupcakes can't account for everything. Children faced with moochers of their own will find only a modicum of consolation here. (Picture book. 5-8)