From the section called Welcome To RAWR!:
The Land of Monsters is in peril!
From deep in the Land of Dreams, Nightmare sends his minions to collect the Imagination Shards of the Dreamers, the children who no longer believe that monsters are the good guys.
The monsters have had enough. They are tired of being called the bad guys. Being a monster used to be a title of respect and decency. It is time for the monsters to fight back.
RAWR!: The Monstrous Adventure Game is a roleplaying game set in the Land of Monsters, the place where the monsters under your beds and in your closets live. The game allows players to pretend to be one of those monsters as they fight against the dreaded Nightmare to protect the very humans who have turned their backs on monsters.
This is the core rulebook for the RAWR! system.