William Mulcahy is a licensed professional counselor, psychotherapist, and supervisor of the Cooperative Parenting Center at Family Service in Waukesha, Wisconsin. Previously he has served as a counselor at Stillwaters Cancer Support Services in Wisconsin, specializing in grief and cancer-related issues, and worked with children with special needs. Bill's short stories have appeared in serveral publications. The Zach Rules series books are his first books for children, merging his passions for good storytelling and providing counseling-like tools to help children live healthier, happier lives. Bill lives in Summit, Wisconsin, with his three sons who played their own role in the creation of the Zach Rules series.

Darren McKee has illustrated books for many publishers over his twenty-year career. When not working, he spends his time riding his bike, reading, drawing, and traveling. He lives in Dallas, Texas, with his wife Debbie.