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....

Almost nothing could be as bad as finding out your mother is Visser One, the most powerful leader of the Yeerk invasion of Earth. But it happened to Marco. He knew there'd come a time when he'd have to face her again, knowing that the Yeerk in her brain has taken his mother away....

Someone's looking for Tobias. Someone who says she's his long-lost cousin. Tobias isn't sure the person is telling the truth, but she's really nice, and knows a lot about him. And what she tells Tobias definitely gets his attention....

Jake's made an amazing discovery. There may be other people who know about the alien invasion of Earth. Others who know about the Yeerks. Jake finds a website devoted to revealing the existence of the Yeerks, but he and the other Animorphs suspect it might be too good to be true....

Jake and Tom's maternal great-grandfather dies suddenly. Their mom immediately travels out of state to help make arrangements for the funeral. Jake, Tom, and their father are to follow in two days when their dad can take off from work....

Things were already really weird. Fighting aliens. Battling to have Earth. And still trying to be normal. Marco and the other Animorphs are almost used to it. But things are changing. The Yeerk invasion of Earth started out passively, secretly.

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....

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.

Eleven-year-old Willodeen adores creatures of all kinds, but her favourites are the most unlovable beasts in the land - strange beasts known as 'screechers'....

The Yeerks are finally starting to realize that the "Andalite bandits" are probably not aliens at all. That maybe they've been dealing with humans all along. And no one -- especially the newly appointed Visser One -- is happy about this revelation.

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.

David, the traitorous Animorph, is back. When the Animorphs decided to give another human being the power to morph, it was one of their biggest mistakes.

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.

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....

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?

A single Arn, Quafijinivon, the last member of the race that created the Hork-Bajir has survived. He has seen his entire people wiped out. He has seen the Hork-Bajir enslaved. Now, after a lifetime of planning and plotting, he wants to get his revenge on the Yeerks....

The pint-sized Helmacrons may have departed Earth, but they haven't finished causing trouble for the Animorphs and Ax. They left behind a damaged ship—containing morph-tracking technology. Now the Yeerks have found the ship, and are launching a full scale Animorphs hunt....

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....

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.