All the Worlds' Monsters is a series of fantasy role-playing game supplements published by Chaosium from 1977 to 1980.

[1][2][3] Edited by Steve Perrin and Jeff Pimper, All the Worlds' Monsters is a fantasy game supplement that lists many monsters from the campaigns of Dungeon Masters across the US, none of which had been published for Dungeons & Dragons (D&D) before and most of which were original creations.

"[7] Don Turnbull reviewed All the Worlds' Monsters Volume II for White Dwarf #12, giving it an overall rating of 5 out of 10, and stated that "my conclusion is very much the same as for volume I. I with the editors had been a little more discriminating, ruthlessly chopping out the uninteresting and the 'randomly-generated' monster and perhaps lowering the price of the final version.

"[8] Steve Jackson reviewed All the Worlds' Monsters, Volume III in The Space Gamer No.

Otherwise, recommended mainly for diehard D&D people, or Runequest fans who want to populate their world with some rather silly creatures.