Magical friends Unicorn and Yeti learn what it means to play fair -- in fun and unexpected ways! Pick a Book. Grow a Reader! This series is part of Scholastic's early reader line, Acorn, aimed at children who are learning to read. With easy-to-read text, a short-story format, plenty of humor, and full-color artwork on every page, these books will boost reading confidence and fluency. Acorn books plant a love of reading and help readers grow! Yeti thinks triangles are the best shape.