Animals are a common feature in Katherine Applegate’s writing. Her Animorphs series, written with her husband between 1996 and 2001, features a group of young friends who transform into different animals to resist an alien invasion of Earth. Applegate’s love for animals inspired her to take up writing since the craft lets her research and explore animals most people don’t encounter in their day-to-day lives. As the Animorphs protagonists transform between human and animal forms, their perspectives likewise shift and the protagonists must balance their human minds with their new, animal instincts. The series touches on themes like morality, coming-of-age, and dehumanization. In an interview, Applegate said her goal was to instill in readers “respect and awe for the natural world” (“K.A. Applegate” Kidsreads.com).

Since then, Applegate has written several books from the perspectives of animals and plants, including The One and Only Ivan (2012) and its sequels, as well as Wishtree (2017). Applegate uses these unconventional points of view to explore nature, animals, and humanity through a unique lens. Her interest in the animal perspective deepened with her research for The One and Only Ivan. The book is told from the perspective of a gorilla who lives isolated behind glass at a mall, and it’s based on the real-life Ivan who spent 27 years similarly isolated at a circus-themed mall in Tacoma, WA.