Concocting an awkward title based on the original plus the musical's Once Upon a Mattress (1959), Campbell updates the tale (bent on self-determination, ``Princess Esmerelda'' runs away to escape marriage to a toothless older man; ``Prince Hector'' drives a red sports car; etc.) and extends it from Andersen's page or two to a lengthy story full of whimsically satirical descriptions. The result is amusing, though it's ironic that- -while lampooning everything else—Campbell misses Andersen's point about the princess and the pea. (And it's unconscionable not to mention him anywhere.) New Yorker cover artist Young makes an excellent picture-book debut with striking, beautifully designed illustrations and a luminous, sophisticated palette akin to Petra Mathers's; her wryly expressive characterizations are nicely in tune with the story's tone, and she offers plenty of intriguing details. Not essential, but fun. (Picture book. 5-10)