Rather than focus on a recalcitrant child, Edwards (Some Smug Slug) reverses the typical plot of a book about polite manners and places a child in charge of a slurping, tantrum-throwing mule. Throughout, the narrator directly addresses the reader: "What would you do if a mule knocked on your door one day and said 'I've come for lunch'?" In a series of familiar situations, made humorous by the cumulative recounting of the mule's discourteous behavior, the boy amiably civilizes his guest: "Mule, eat your food quietly." When the mule predictably replies, "Won't!" the boy delivers a mature response: "Then we won't be able to play with my train set after lunch." The mule brays and stamps his hooves ("You'd ignore him until he stopped, wouldn't you?"), and each time, the boy wins over his belligerent companion with consistency and patience. There's plenty of flying spaghetti and action in Nascimbeni's (Small Brown Dog's Bad Remembering Day) fiesta-bright, black-lined illustrations, which pump up the energy in full-bleed spreads of the mounting chaos. When the mule begins to shape up, a series of vignettes demonstrates the rewards of the newly forged friendship as the two ride the boy's train, play hide-and-seek, etc. (and the boy's dog acts as a barometer for the proceedings). A refreshing twist on the value of knowing one's P's and Q's. Ages 4-8. (Aug.)