From publisher blurb:
From the mind of H.P. Lovecraft, this release of The Manual of Mutants & Monsters provides game stats on the Mi-Go, a truly alien form of evolved fungi that have come to Earth to plunder our resources, study us, and eventually colonize our planet. They are master surgeons and engineers of bio-technology who work from the shadows, using the bodies of our own people against us.
Includes game statistics on the mi-go, along with samples of some of their more common technology. Rounding out this product are three caper ideas for using mi-go in your game, including how they may be involved with granting player characters their powers, and 1 new extra and 1 new advantage.