I really loved Sidekicks. I loved it so much I read it all in one afternoon--the same day I got it! The characters are: the dog Roscoe, aka Metal Mutt; the cat, Claw, aka Static Cat; the hamster, Fluffy; and a chameleon, Shifty, aka The Chameleon. The Chameleon is very funny! He says and does really funny things.
Their owner is a superhero and they want to be superheroes too, and in the end they are. The owner's name is Captain Amazing and he can fly and he's allergic to peanuts. He fights crime and his pets do too. One of my favorite parts is that there's a giant hippo at this restaurant who is hogging all the food and he's eating some fish when the chameleon becomes invisible and makes the fish look like it is actually alive which scares the hippo and he runs away.
I would recommend this book to anyone who likes comics or superhero animals!