Compiling and updating monsters that originally appeared in Volos Guide to Monsters and Mordenkainens Tome of Foes, this book presents friends and foes for any D&D campaign, many of them accompanied by the comments of Mordenkainen. The wizard has faced many of these monsters and peoples on numerous wondrous adventures. Now its time for you to venture forth and face these creatures yourself!

Includes over 250 monsters. Updates to the monsters include making spellcasters easier for Dungeon Masters to run; giving many monsters more damage and resilience; and improving the organization of the stat blocks themselves.
Includes over 30 playable races. Brings all the games setting-agnostic races into one book, complementing the races in the Players Handbook.
A multiverse of lore. Includes updates to monster lore that refocuses the stories on the D&D multiverse, rather than on any particular world.