From publisher blurb:
This new monster project began with an idea, something along the lines of one new monster of each of the various types. After that came the brainstorming for new monsters of those 13 types (aberration, animal, construct, dragon, fey, humanoid, magical beast, monstrous humanoid, ooze, outsider, plant, undead, and vermin). Although when it came to the animal entry I decided to have two creatures, so I suppose you’re getting (15) “new” monsters (since the animal and vermin entries have two each).
Then I contacted Axel from Headless Hydra Games, and pitched him my idea, and he liked it enough to “greenlight” it … and the rest is history.