Yoon is an award-winning author-illustrator of nearly two hundred books for children, including "Duck, Duck, Porcupine!,” the Penguin series, the Bear and Floppy series, "Be a Friend” and most recently, “My Kite is Stuck! and Other Stories.” She studied art and design at the Art Center College of Design in Pasadena, California, and now lives in San Diego with her family.