As a bony little kid, author Andrew Biel would tap his fingers along the lengths of his tibia or ulna and exclaim, "These are some crazy, long bones!" Over the years, he learned more about the skeletal system, wrote a best-selling textbook entitled Trail Guide to the Body, and now enjoys using his bones to hike, kayak, and cross-country ski.

Robin Dorn is a painter and scientific illustrator, specializing in human anatomy. She likes to keep in touch with her whimsical side in the company of such characters as Mr. Bones.