Bestiarium is ND Hobbies' book of monsters and this first release, Scales & Decay. This is a fully illustrated, hardcover book, filled with Dragons and Undead for the 5th edition of the world's greatest role playing game.
In this book the monsters are divided into three main parts.
Dragons. Completely new dragon families and many versions of them, with Stat Blocks for the 4 regular ages. But each true dragon will also have a Scalable table for the 12 old school ages.
Undead. There are new types of the good old zombies and skeletons. But also very different and mechanically interesting undead.