- Narrator: Jake
A group of five young teenagers cut through an abandoned construction site at night to get home, only for a spaceship carrying a dying alien prince to land in front of them.
Tropes
- Always a Bigger Fish: Rachel acquired an elephant in hopes that the biggest land creature on Earth would do the most damage to the Yeerk pool. Visser Three morphs into an eight-headed fire-breathing alien hydra that manages to be bigger than Rachel's elephant, forcing the Animorphs to retreat.
- The Call Knows Where You Live: While trying to reassure themselves that the Yeerk invasion can't be as bad as Elfangor made it sound, Jake and Marco realize that Tom is a Controller.
- Didn't Think This Through: Jake wanders into the tiger pit to acquire one of them, realizing too late that the tigers would take exception to a strange human walking into their turf. Luckily, acquiring causes a trance in the creature being acquired, allowing Jake to escape while the tiger shakes himself off.
- Downer Ending: The Animorphs fail to save Tom like they intended, realize the Yeerks have much more influence than they initially thought, they're forced to retreat from the Yeerk pool when Visser Three arrives, and Tobias gets trapped in morph. They conclude they have no choice but to fight back.
- Early-Installment Weirdness: Two examples, both fixed in the graphic novel rerelease.
- Visser Three acts like he's meeting Elfangor for the first time, when The Andalite Chronicles showed that Elfangor played a part in Visser Three's creation. In the graphic novel, Visser Three instead greets him with "You've become a legend since we last met."
- Jake is able to communicate telepathically with Tobias while the former is still human and the latter is in morph. In the graphic novel, Jake isn't able to do this, and Tobias concludes that you have to be in morph to use thought speak.
- Eaten Alive: Elfangor, too weak to morph or escape, is caught by Visser Three, who morphs into a giant alien monster and eats him whole.
- Evil Principal: When they sneak into The Sharing, the Animorphs learn that Mr. Chapman, their school's vice-principal, is also a Controller.
- First-Episode Twist:
- Jake learns that his brother Tom is a Controller. The rest of the series is devoted to Jake trying to free him.
- Tobias gets trapped in the form of a red-tailed hawk, possibly on purpose.
- Killer Gorilla: Marco acquires a silverback gorilla as his battle morph.
- The Mind Is a Plaything of the Body: The Animorphs learn that animal instincts can overwhelm their human intelligence.
- When morphed into a cat, Tobias can't stop himself from playing with string.
- When morphed into Homer, his dog, Jake begins barking at the real Homer.
- When morphed into a lizard, Jake eats a spider while horrified by what he's doing the whole time.
- Mr. Exposition: Elfangor gives the kids a rundown on the secret war being fought on Earth, the invading Yeerks, and the species they've enslaved through private thought-speak as he gets surrounded by Controllers.
- Panthera Awesome: Jake acquires a Siberian tiger as his battle morph.
- Refusal of the Call: Aside from Tobias, none of the kids are eager to try fighting the Yeerk invasion at first. Unfortunately for them, the Yeerk invasion is closer to home than they realized.
- Shapeshifter Mode Lock: Before they ever use their powers, the Animorphs learn that staying in morph for more than two hours will trap them in that form forever. Tobias keeps skirting the clock for most of the book, until the end where he arrives at Jake's house and admits he's been a hawk since he morphed in the Yeerk pool the previous night.Tobias: <I guess this is me from now on.>
- Voluntary Shapeshifting: With the morphing cube, Elfangor gives the kids the ability to absorb the DNA of any animal (or alien) they touch, then transform into it. There are a few limitations that every morpher is subject to: First, they can't go directly from one morph to another, needing to change back to their original form before they can use another one. Second, DNA can't be absorbed while in morph, nor can it be absorbed from a morph. And third, staying in morph for any longer than two hours will cause the morpher to be trapped in morph, unable to morph at all.
- War Elephants: Rachel acquires an African elephant, the biggest land creature on Earth, as her battle morph.
