From publisher blurb:
In the various worlds that one may travel in the 4CX multiverse, there will be monsters, creatures of legendary stature and mythological might. Within the countless realms, one will also encounter more common beasts, some wild and dangerous, others docile and benign. Herein you will find descriptions of many marvelous creatures that your adventurers may happen to cross paths with.
The 4C Expanded Monstrous Compendium is designed to be a resource for game masters using the 4C Expanded rules set. Each creature will be assigned a Threat Level to help the GM to decide, at a glance, whether to use a specific creature against the characters based upon their own power range. The creatures collected here are mostly found in common mythological stories and tales which should be familiar to everyone.