Thinking of dabbling in Carcosan sorcery but worried you may still have some pesky shred of humanity lurking in your withered heart? Want to raise an army of Amphibious Ones to smite your childhood enemies but aren’t quite ready to pay the awful price? Grab your Potassium Axe, bro. We’re off to the Radioactive Desert, where Mummy Brains dot the wasteland like cat turds in the neighbor kid’s sandbox!
Mummy Brains can cast rituals with no need for sacrificial hoo-ha, which makes them not only monster, but also artifact and NPC. The Evil Brain is a venerated concept in comic book sci fi, and one that neatly circumvents Carcosa’s most lurid details. Just put any ritual you don’t want to deal with into the mind of a mummy brain. Plus, questing after a disembodied brain beats a crappy journey to Mordor any day.
Can you prevent Mum-Ra from getting the old gang back together and summoning Nyarlathotep? Who will stop Krang the Konqueror from using his robot body to terrorize the Bone Man village? Will Grodd find the Hypothalamus of Hodag before the Mi-go get their chitinous claws on it? What happens when a zombie eats one?
Honestly, Mi-go and Mummies seem like great opposing factions for this whole dumb experiment. Imagine the opening scene of Temple of Doom, but with Mummies, Mi-go, Jale slave girls, and the PCs all fumbling over a really top-shelf brain cylinder containing the Brain of Nurhachi.
Of course, merely finding a mummy brain won’t make it cooperate. In the unlikely event that it doesn’t try to kill you, it’ll probably want to strike some kind of bargain for something it wants (like a working body, or a really nice brain pillow). In fact, PCs may be forced to bargain with them given their wholesale immunity to pretty much everything.
Good luck with that.