From publisher blurb:
Intelligent Melee Fighters and Deadly Ranged Combatants
Do your PCs need to hire a tracker that can deal serious damage? Does your upcoming session need someone that can bring the pain to the toughest members of the group utilizing unexpected tricks? Are you seeking ideas for the terrible power at the end of your campaign? The Book of Beasts: Slayer Codex has the solutions you need, arming Game Masters of the First Edition of the Pathfinder Roleplaying Game with the following:
20 ready-made slayer characters, one for each level of play
Tactical combat recommendations for every character, helping you to quickly and effectively run the NPC in a fight
Personalities and details to give you ideas on how to use the characters both in combat and in roleplaying interactions