Bestiarum
From Halopedia, the Halo wiki
The Bestiarum is a compendium of partly canon information about the various species in the Halo universe.
It is included exclusively in the Legendary Edition and Collector's Edition of Halo 3. In the Collector's Edition it is a physical book, while in the Legendary Edition it is included in an expanded digital form on the Legendary-exclusive DVD.
The book has renders and a grid outline of sorts of the entities of the Halo Universe. It also includes information about the species' homeworlds and the Forerunner Technological Achievement Tiers. It is written from a Forerunner point of view and cites its sources including communications from The Arrays, The Shields, 2401 Penitent Tangent, and 343 Guilty Spark. It is worth noting however that the aforementioned Monitor's observations are "under investigation".
