From publisher blurb:
Since the release of the first bestiary, the first monster book, there have been those who asked - can I play something exotic, can I play a monster instead of a regular character?
In this release of the Monster Classes series, you have the opportunity to play as one of two outsider races - the angellic hound archon or the demonic succubus! As a member of these races, your experience playing in the Pathfinder Roleplaying Game is sure to be unique and filled with unexpected situations.
This book includes two monster classes - the hound archon and the succubus, along with the associated feats necessary to build interesting characters, that at the same time are true to the concept presented in the Bestiary.
