Millie, a pig, knows ``everything there was to know about mud.'' She loves it. Despite the increasingly urgent (and amusingly rhymed) warnings of her farmyard friends, she goes on sitting in a mudhole, pretending to be a lily pad or perhaps a cherry in a chocolate milk shake. At last, she sinks too deep to extricate herself and has to be rescued by all nine other animals pulling in a row with the pig keeper. Finally, like Russian folklore's turnip, she pops out, still fantasizing and unperturbed. The story, as silly as Millie herself, should amuse newly independent readers—who will also find that the simple language and the cumulative repetitions make reading a breeze. Wickstrom's lively action, broadly comical animal characters, and sunny colors add substantially to the attractions. (Young reader. 4-8)