Mordenkainen's Tome of Foes

[William Bryan]

"Discover the truth about the great conflicts of the D&D multiverse...."

http://dnd.wizards.com/products/tabletop-games/rpg-products/mordenkainens-t ome-foes

I for one am excited for 5E to expand upon the fiendish part of the multiverse. And I hope it leads into a planar campaign!

[Sqn Cdr Flashheart]

I really liked Volo, this looks like a planar version

[hiiamtom]

On ItMeJP's second stream with Mearls, he announced that this book with be 50% CR 10 and above creatures which is pretty interesting.