In The Lives of Christopher Chant, Fenning is one of the two boys Christopher meets and befriends on the train enroute to boarding school.  Along with the other boy, Oneir, the three boys try to call themselves "The Terrible Three," but the other boys all call them "the Three Bears because Christopher is quite tall, Fenning is quite short, and Oneir is right in the middle.

Apart from going cricket mad with his friends, and spending fun nights taking turns reading out loud from the unexpurgated edition of The Arabian Nights after lights out in the dormitory, Christopher and his friends don't have much time to spend together.  After less than a year at school, Christopher is pulled away to be raised by Gabriel de Witt at Chrestomanci Castle.