Book excerpt: Poky, the mischievous star of the Golden Books classic "The Poky Little Puppy," once again digs a hole under the fence and wanders off. This time he finds himself on Sesame Street, where he meets everyone's favorite Sesame Street characters, among them Elmo, Grover, Big Bird and the Twiddlebugs. "The Poky Little Puppy Comes to Seseame Street" is a story children will want to read over and over again.