Animorphs

One of the author's favorite books, The Lord of the Rings, lent several words and images to Animorphs: the Sindarin plural word for Orc, "yrch", became Yeerk; the flaming red Eye of Sauron inspired the Crayak, and Ax's middle name, "Esgarrouth", is based on a town in the books called Esgaroth.

All books after The Unknown were dedicated to Applegate's first daughter, Clara, under her former name, as well as Applegate's husband and co-writer, Michael.

Her daughter was born premature in 1997, and Applegate worked on the Animorphs series at night, in the lobby of the hospital where she was in Neonatal Intensive Care (NIC).

In another interview, Applegate stated that she originally wanted the alien Andalite to have more standard and familiar forms, but was told by Scholastic to be more creative with the designs, which led to her giving them such a distinctive look.

According to the Anibase (an officially-produced, Flash-based piece of software once available on the official Animorphs website with detailed information about each book), Applegate did not make up the titles for the Animorphs books: it was up to the Scholastic editors to create the titles for the books based on the outlines provided by the author, having to select a word that not only fit the book's storyline, but sounded good with the characteristic "The" preface.