From the back of the book:
Monsters abound. They litter the halls of our collective games like so much debris; wandering monsters, laired beasts, plane walkers, horrid thoughts that linger upon the edge of our imagination. Monsters abound, but as any gamer of any strip knows, you can never have too many creatures for they are the grist of the mill that is our game.
The early days of gaming saw some of the most classic and amazing creatures. Weird beasties derived from the minds of people influenced by a genre of fiction that was in its prime, when fantasy truly meant the fantastic. Castles & Crusades has touched upon them from time to time, but by and large they have remained in the background. Until now. Classic Monsters revisits them all from the tarrasque to the peryton, from the mighty-small dune stalker to the nightshade, this book brings it all back to the table.