It’s not the most in-depth or longest supplement, but earlier today, Wizards of the Coast released a 38 page free to download supplement for Dungeons & Dragons. Plane Shift: Zendikar is meant to be used in conjunction with the D&D 5th edition ruleset and The Art of Magic: The Gathering – Zendikar book to give dungeon masters and players the resources they need to adventure within the lush world of Zendikar.
Available in PDF format, Planeshift: Zendikar contains stats for four custom playable races; Goblins, Merfolk, Vampires, and Kor. Also included is a bestiary, with suggested stats for native creatures like Baloths and Felidar, and then other entities like Angels and Eldrazi, even the titans.
If well received, Wizards of the Coast will likely be following this supplement with another for their Gothic horror themed plane Innistrad, which they also will be releasing an art book for in July of this year along with the second set of the Shadows Over Innistrad Block.