12 Fascinating Insights Into the Animorphs Book Series

In 1996, Scholastic released The Invasion, the inaugural book in the Animorphs saga. This children's novel introduces a race of blue centaur-like aliens who grant human children the extraordinary ability to morph into any animal they touch. With these powers, they must protect Earth from the Yeerks, a parasitic alien species that takes control of human minds by crawling into their ears.

Even if you're not well-versed in the complex Animorphs universe, you’ve probably seen its iconic covers. The series was everywhere during the late 1990s and continues to resonate today. The 2020s have brought new Animorphs graphic novels and a movie adaptation is in development. Whether you read every book or just flipped through the mini flipbooks tucked into the corners of pages, here’s all you need to know about this timeless sci-fi adventure.

1. The author behind Animorphs, K.A. Applegate, is actually a duo of writers.

While many recognize Katherine Applegate as the author of Animorphs, the series was a collaborative effort. She co-authored the books with her husband Michael Grant under the pen name K.A. Applegate. Both are accomplished writers with separate careers beyond Animorphs. Katherine has written the Endling trilogy and the Ivan & Friends books for young readers, while Michael is known for the YA series The Gone.

2. In just five years, fifty-four books were published ...

Between 1996 and 2001, Scholastic released 54 books as part of the main Animorphs series. That’s an impressive output, especially for a two-person team. However, Katherine and Michael weren’t working alone. In a 2011 Reddit AMA, Katherine Applegate revealed that books 25 through 52 were ghostwritten. Though the original authors maintained creative control, providing detailed outlines for each book, they wrote the final two installments themselves.

3. ... And that doesn't even include the spin-off series.

Dedicated Animorphs fans know that the journey doesn’t end with the 54 core books. The franchise expanded to include several spin-off series, like Megamorphs (which shifts to a different character’s perspective with each chapter) and The Animorph Chronicles (which tells the story from the aliens' point of view). Additionally, there was a choose-your-own-adventure-style series called Alternamorphs.

4. The idea for Animorphs came to life next to a dumpster.

The creation of Animorphs proves that inspiration can arise from the most unexpected moments. One evening, Applegate and Grant were walking through their Sarasota, Florida, apartment complex when they decided to brainstorm a new children’s series. Katherine later explained on Scholastic’s online Animorph's database, the Anibase: “I wanted to write about animals—somehow putting kids in the minds of animals.” As they walked past a dumpster, the first piece of the idea came to them: kids turning into animals. The next step came when Grant suggested adding an alien invasion, and the concept grew from there. As Applegate recalled: “So, Animorphs was born on a hot summer night beside a dumpster in Florida.”

5. The series was originally intended to be a trilogy.

The idea that evolved into Animorphs was always intended to be a series, but initially, the writers envisioned a smaller scope. The story began as a trilogy titled “The Changelings.” However, Scholastic proposed renaming it Animorphs, which the authors felt was a more fitting choice.

6. The main characters almost looked very different.

The title change wasn’t the only modification during the development of the series. When writing the first book, K.A. Applegate didn’t initially settle on the core group of characters fans know today. Jake, who was initially called Matt, had a younger brother in the early drafts, and Cassie didn’t appear until later drafts.

7. The authors took time to study animals.

Although the story revolves around an alien invasion and shape-shifting teenagers, the creators of Animorphs made an effort to remain scientifically accurate wherever possible. Katherine Applegate shared with KidsRead.com that she strived for realism when portraying the world through the perspectives of different animals. “When Tobias becomes a hawk, I want readers to experience the world as a hawk would—feeling the warm air currents and diving toward the ground to hunt,” she explained. “When Marco turns into an ant, I want to convey the ant's lack of individuality, existing in a world of scent and touch. When Cassie becomes a dolphin, I want the reader to feel the sensation of water rushing past and to experience the leap from the cold ocean to the warm sky.” To make these moments vivid, Katherine conducted thorough research, consulting her library, zoo curators, and zoologists. At times, she even interacted directly with the animals she wrote about, such as when preparing for Tobias’s hawk transformation by visiting a raptor rehabilitation center.

8. Some alien words have unexpected origins.

Every sci-fi and fantasy writer has their own way of inventing fictional languages, and the alien vocabulary in Animorphs had some surprisingly ordinary origins. “How do I come up with names for aliens and the like? Sometimes I just play with letters and sounds until something clicks,” K.A. Applegate explained in a Scholastic Q&A. “Occasionally, I’ll take a word from my surroundings and tweak it or reverse it. For example, the Andalite word ‘Nothlit’ came from seeing the word ‘Hilton’ through my window. I simply rearranged the letters until I got ‘Nothlit.’”

9. The covers used a Hollywood special effects trick.

Even kids from the '90s who never read Animorphs likely recognize the books from their striking covers; each one depicts a character gradually morphing into an animal. This transformation was achieved using a digital effect called morphing, which blends two images into a single shape through technology. While it might seem a bit outdated today, the technique was quite advanced for its time. David Mattingly, the artist behind the covers for Animorphs books No. 4 through No. 54, revealed that the morphing technology was first developed by Hollywood visual effects artists, before he adapted it for book design. “The first use of morphing, I think, was in the second Terminator movie,” Mattingly shared with Vice. “It was one of the rare instances where I saw something in a movie that was truly new.” (Mattingly got the job because he was one of the first illustrators to adopt computer technology, which led Scholastic’s art director, Dave Tomasino, to reach out. “They knew they wanted someone who could do morphing, so Dave called me up and said, ‘We heard you can do morphing.’ I hadn’t actually done any morphing yet, but I thought, ‘Why not?’”)

10. Most of the cover models didn’t appear on later books.

In addition to creating the morphing effects, Mattingly also photographed the kids and animals featured on the covers. Although the five main characters each starred in multiple books throughout the 54-part series, the same cover models weren’t always used. “The kids grow too fast,” Mattingly explained to Vice. “By the time they came back, they’d gone through puberty and looked completely different.” However, there was one exception. For each of Cassie’s books, the same model was used for every cover. Mattingly said, “If I saw her today, she’d probably look about the same—she just never seemed to age, and she was an amazing model, very cooperative.”

11. The authors weren’t fans of the TV show.

After the book series became a hit, Scholastic brought Animorphs to the small screen on Nickelodeon. The show aired from 1998 to 1999, featuring some questionable special effects and a pre-X-men (2000) Shawn Ashmore. While the series developed its own fan base, the creators of Animorphs were not impressed. “Oh, we hated the TV show. We felt it insulted the hundreds of thousands of kids who read the books,” Michael Grant shared in a 2016 Reddit AMA. If it had been up to them, they would have preferred an animated version. “We told Scholastic that going ‘live action’ was a bad idea, considering that animals, child actors, and special effects are some of the most costly things in Hollywood, second only to hiring Tom Cruise,” Grant explained.

12. A new Animorphs movie was announced in 2020.

In 2020, news broke that a film adaptation of the Animorphs series would be hitting the big screen. The movie is a partnership between Scholastic and Erik Feig’s production company, Picturestart, known for adapting hit YA franchises like Twilight, Divergent, and The Hunger Games. Although the series authors were initially on board as collaborators, Michael Grant and Katherine Applegate ultimately parted ways with the project due to “creative differences.” Grant later tweeted, “Decisions we hoped to influence were made without us... But we have a policy: we don’t take credit for things we didn’t actually do. Since we weren’t contributing, we walked away.” Fans are still awaiting further details about the movie, such as the cast and release date.