Cranium Rat

An individual cranium rat is about as intelligent as an average child, while normal-sized swarms can rival your average wizard apprentice. Given enough rats, a swarm's intelligence can grow past the intelligence of even an archlich.

Cranium rats speak only through telepathy, and their words are understood in the listener's own language.

These beasts were first created by mind flayers as experimental subjects. Through combinations of magic use and psychic influence, mind flayers imparted psychic abilities to rats, granting them sapience, an unintentionally, the ability to access magic themselves. Several cohorts escaped the underground lairs over the millennia of experiments, and became a viable feral species, surviving in abandoned tunnels and eventually escaping to the wilds beyond.  

Notable Events

Thywicket was infested by cranium rats, and many of them fled into the coral forest as the city began to pupate. While infesting the city, the glow from their brains were mistaken as light from the caterpillar's bioluminescent street lights. This allowed the rats to move by night, unnoticed, and able to cast domination spells or alter memories the few times they were seen. When the party of adventurers arrived to the city, the rats were in the late stages of preparing the city for an early pupation. They had taken over the minds of many workers in the poor district, ordering them to construct a sarcophagus for Gephemassk, the surviving mind flayer from the nearby colony and forcing several to become hosts for intellect devourers.   As the party went to the wizard tower in their search for Folgorath, the cranium rats in the city received a telepathic order: "Retrieve the large green book from the tower". Without clearer instructions, the confused rats swarmed the walls and supports of the tower. Upon finding the crew there, also searching the library, the cranium rats used their psychic influence to dominate Steps Upon Green Hills, passing on their order. Meanwhile, the rats outside began to chew through the stilts holding up the stone tower, causing it to fall and break through the roof of the House of First Ascension. They failed to find the desired book, but succeeded in forcing the church to close down for repairs. During the repairs, mind-controlled workmen were able to install the sarcophagus.