The Blight: Tome of Blighted Horrors (PF)
This book is a Blight GM's best friend; it takes the 24 new monsters and templates to be found in the Bestiary chapter of the Blight GM Guide and breaks them out into a separate book before adding more than 50 additional new Blight and Between up to over 80 new monsters. In addition, the book provides new universal monster rules and compiles new subtypes and feats along with all the subtypes and feats in existing Frog Gog Games Tomes of Horrors into a single book for ease of reference. To round it all out, the appendices provide a complete listing of the monsters in this book by type and subtype, by CR, and by terrain, as well as, lists of monsters as PCs and monsters that can be trained. Don't go into a game with your players unarmed.
Take The Tome of Blighted Horrors with you, and let them know the danger of venturing into The Blight.