From publisher blurb: Building on the mechanics from Bloodline Levels, Monstrous Bloodlines presents 12 new bloodline classes for your d20 System fantasy game: aboleth, aranea, behir, chuul, cloaker, couatl, harpy, lamia, naga, rakshasa, sphinx and treant. Each has its own unique level progression and class abilities, giving each its own unique flavour, and giving you more options for your game.