Yamba's Army: The Callers Book 1

Yamba the pygmy possum, sets off to join the Beast Navy submarine service. The first of her kind to leave their home tree in the Australian Alps for a thousand years, she knows a lot about martial arts, sausages and cupcakes - and not much else. Joining forces with a wombat, platypus, and bandicoot, they head for the coast to join the battle against alien invaders. Bucking the trend, there are no vampires or Zombies involved. Yamba's Army is without a doubt, at least the second best middle grade adventure fiction about wombats in submarines that you are going to find this week.