Sapience can be a terrible curse. And few creatures experience that pain more deeply than the brain mole monarch. The diet of psychic energy that enhances their intelligence to near-human levels is the very same diet that encourages the magical tumors that metastasize through their bodies. Thus, hard on the heels of the arrival of their self-awareness comes the knowledge that they are sick, that their bodies are betraying them, and that they are mortal. Worse yet, a brain mole monarch suffers this discovery alone, since the other unascended moles in its nest are just dumb animals by comparison, little more than components for the hive mind.
And so, desperate to leave a mark on the world in the short time they have, brain mole monarchs scheme, plot, plan, carve monuments, hunt humanoid candidates for mind swapping, attempt risky experiments, push their psychic-gestalt-linked kin to take ever-greater risks, and generally cause havoc in their wake.
One more note: Last entry we covered the theory that, since brain moles have six limbs, they might be from another planet (that all hexipedal and/or psychic creatures come from space being a common trope in pulp fantasy). But there’s another tradition, especially from sword & sorcery fantasy and 1e AD&D, that says that psychic creatures tend to come from Deepearth/the Underdark (or whatever your preferred name is for the subterranean realms). And brain mole monarchs fit well into that mold too. There’s another hook as well: One of the only evil gnomish deities, Urdlen the Crawler Below, resembles a giant naked mole rat, just as Pathfinder’s brain moles do. If you don’t mind mixing Pathfinder and Greyhawk/Realms lore, brain mole monarchs might be Urdlen’s children, recipients of his mental gifts but cursed by the dark energies that long ago curdled his soul…
A wave of strange trances strikes the city of Nerislann. The victims seem to suddenly understand no Common, fear bright light, and eagerly eat bugs and worms. Often they are reported to have stolen books or other small objects. Sometimes their minds return—always with tales of tunnels, and darkness, and the strange pressure of chittering minds inside their own—but others remain trapped in an animalistic state. A brain mole monarch has been collecting humanoid minds and depositing them in the pale bodies of her servitors. Soon she will have one trapped mind for every planet that tracks across the night sky…
Tormented by tumors that wrack her with pain and rendered her nearly blind, a particularly bright brain mole monarch, Soilsworn Fenn, has turned to the same answer so many death-fearing humanoids do: necromancy. Now she rules an army of tiny skeletons, zombies, and even an attic whisperer or two (that latter drawn by the negative energy and the plethora of rodent skulls to choose from). Hoping to cause a wave of deaths whose energy she can harvest for a ritual, Soilsworn Fenn has set her servants to work on destroying the dam that overlooks a nearby town.
Adventurers exploring a dungeon come across a strange chamber whose floor is almost entirely taken up with a miniature city, and whose walls are lined with images telling a saga of some sort. A brain mole monarch (whose mind is supposedly represented in the structure and street layout of the bizarre model city) seizes the opportunity to induct the adventurers into the rites and articles of faith of her “priesthood,” so that the outside world may know of her glory when the tumors take her.
—Pathfinder Bestiary 5 47