This sourcebook, written by D&D designer Robert J. Schwalb (see "Robert J. Schwalb"), is a 5E updated edition of The Book of Fiends, which was originally released back in 2005. The tome focuses on the fell creatures of Hell, the Abyss, Gehenna, and beyond. It contains over 130 fiends and monsters with Challenge Ratings ranging from 0 to 31, and adds to the information found in core 5E books. This book also expands these creatures' evil planes of existence.

It will retail for $49.45 upon release.