That accommodating bull of Irish folklore--the one with the napkin full of feasts in his left ear and the magic strength in his hide--dominates only part of this 100-plus-page elaboration on the lively old tale. Here Billy Beg's trouble starts when his father Red Brian, a king (""in those days being a king meant mostly that you had more cattle than anybody else from miles around""), marries a wicked enchantress determined to get rid of her stepson's good friend the bull. And so boy and bull depart, hiring themselves out up and down Ireland, building a wall for the King of the Scots and another for the King of China who wants one like it only bigger. But it's back to a sad, sere Ireland when the bull complains that the Chinese grass ""just doesn't stick to your ribs""; there the bull at last meets his match and, with the strength he bequeaths to his companion, Billy Beg slays giants (""Fe fi fo feg/ I smell the blood of Billy Beg""), rescues a maiden, and at last sees the land and his own mother restored to their proper condition. Curley has a high old time with his traditional material, and readers who aren't purists will enjoy going along for the romp.