Animorphs

"Marco never wanted to be an Animorph. He never wanted the ability to change into animals, and he definitely didn't want to be a member of the planet's only defense against a secret alien army. All Marco wants to do is take care of his dad, the only family he has left after his mom died two years ago. If anything happens to Marco, his dad will be alone. But something big is about to change for Marco--something that will give him a reason to fight"--Provided by publisher.