Generally, I just go with the traditional fantasy stuff. Low CS undead? Skeletons and Zombies. High CS undead? Liches, Death Knights and Vampire Lords. Low CS Monsters/Rogues? Direwolves and Goblins/Bandits. High CS Monsters/Rogues? Dragons.
I've been reading a book series that describes in pain staking detail the monsters of the Netherworld. It's good to know there is a reference guide for those.
What book?
