The definitive d20 System resource for enhancing and modifying the monsters in your game. • More than 60 new feats for monsters of all types. • More than a dozen new prestige classes, including the thunder hammer giant and draconic tyrant. • Dozens of new special attacks, special qualities, and traits conveniently broken down by creature type. • New templates such as the chaos dragon and relentless undead that can be applied to a variety of creatures to create devastating and interesting new breeds of enemy. • Detailed guidelines on adding abilities to monsters and adjusting their CRs to reflect the new challenge for PCs. • A comprehensive discussion on using monsters effectively in your game, and suggestions on how to modify existing monsters to present exciting and mysterious new challenges to your players every session. • In-depth suggestions for combining core feats, skills, classes, and magic items with different types of monsters. • Sample creatures in each section showcase the new rules and make suggestions on how to effectively integrate them into your campaign.