Katherine A. Applegate

The Earth is being invaded, but no one knows about it. When Jake, Rachel, Tobias, Cassie, and Marco stumble upon a downed alien spaceship and its dying pilot, they're given an incredible power - they can transform into any animal they touch. With it, they become Animorphs....

There's something pretty weird going on in the woods behind Cassie's house, the place where Ax and Tobias call home. It seems the Yeerks have figured out one very important fact: Andalites cannot survive without a feeding ground....

Ax is an Andalite, an alien, stranded on a strange planet he's sworn to defend, even though it's not his own. Since the Animorphs rescued him, he's fought at their side, and in that time they've come to consider Ax a friend. But deep inside, Ax knows he isn't their friend....

We found out who Visser Four is. And he has found the Time Matrix, the machine Elfangor had hidden in the abandoned construction site. The same place we met him on a night none of us will ever forget. Especially me. Now Visser Four has the Matrix, and he plans to use it to become Visser One....

Rachel is still reeling from the news that the Earth is secretly under attack by parasitic aliens known as the Yeerks. And that she and her friends are the planet's only defense....

Marco's mom is back. But she's not Visser One anymore. Marco's not even sure if she's still a Controller, but he's determined to find out. No matter what it takes. No matter what might happen. Marco wants his mom back.

Dak Hamee is a unique Hork-Bajir. His people call him a seer. He learns more quickly and completely than the rest of his docile race. Hork-Bajir like him are born once a generation.

Something is very wrong with Ax. He's sick, and the Animorphs don't know what to do about it. They can't take him to the hospital. They don't know how to contact the Andalite home world. And Ax is dying. Cassie and the other Animorphs come up with a plan.

The last time Rachel and her friends entered the giant Yeerk pool beneath their town things went very bad. This time they plan to be careful, and sneak in as roaches, just to spy. Once they're inside, though, the team gets caught....

Tobias has gotten used to his new life. He's a red-tailed hawk with the mind of a kid. It was difficult when he first became trapped in his morph, but he's started to come to terms with things....

There's been an accident. Someone crash landed a Yeerk Bug fighter, and the Yeerks have been trying to cover it up - quickly. When Tobias spots it before they get the chance, the Animorphs decide to steal the ship, to show the world that Earth has been invaded....

What's tasty, good for you, and only takes 60 seconds to make? Oatmeal. And because of a strange reaction to the Yeerk's physiology, it's making the would-be invaders of Earth more than a little crazy....

There is an Anti-morphing ray out there. It's purpose: to cause a person in morph to revert to his natural form. And the Yeerks have done a very good job in hiding it. Word from the Chee that the Yeerks are ready to test the weapon. Just one problem: They don't have a test subject.

It all started with the dreams. But Cassie didn't pay much attention to them. She and her friends have been having nightmares ever since they acquired the power to morph....

Elfangor-Sirinial-Shamtul is an Andalite war prince--the one who gave the Animorphs the power to morph. "The AndaliteChronicles" is the story of how this warrior-cadet ended up on planet Earth.

Marco never wanted to be an Animorph. He didn't want the ability to change into any animal he touches. And he certainly didn't want to be one of a handful of kids that are the planet's only defense against a secret alien army. His friends know why he feels the way he does....

Rachel's got some pretty strange stuff happening. She can't control her morphing. One minute, she's doing homework. The next, she's morphing a full-grown crocodile, and - without returning to human form - she becomes an elephant....

The Andalites have returned! The main fleet flew off-course in an effort to stop the galaxy's newest threat – the Rakkam Garoo. But a small crew managed to reach Earth. Now it's up to the Animorphs to decide how to treat their new allies. Can the group be trusted?

The Animorphs have one true ally in their battle against the Yeerks: the sentient androids known as the Chee. So when they discover that the Chee—including their friend Erek—are in trouble, they have no choice but to help.

Ax and the Animorphs are about to have a huge problem. It starts when they decide to morph into mosquitoes in order to slip by some unsuspecting Yeerks, and ends with them stuck in Zero-space with no idea how they got there, no way back to Earth...and no oxygen....