A merry meatball is rolling a path of destruction through a small town. He rolls over pets, petunias, and the library--where he refuses to shush. When he rolls over the mayor herself, the townspeople know it's time. Time to invite the meatball to dinner. . .      Sly humor abounds in this charming, offbeat story that will appeal to anyone who's ever faced a bully--and, of course, to spaghetti fans of all ages.