PINOCCHIO'S UNDOING is a reference to the classic story of Pinocchio, a wooden puppet created by the woodcarver Geppetto. The crossword solutions for this term are LIE and LIES, which refer to Pinocchio's undoing in the story. Pinocchio was constantly tempted to LIE, and his LIES were what caused him the most trouble. His LIES caused his nose to grow longer each time he told one, and eventually led to his capture by the villainous Fox and Cat.