I was reading through the old D&D sourcebook The Scarlet Brotherhood, mostly because (for some reason) it contains the most information about the Olman people (fantasy mesoamericans), when I came upon one of those crazy idea that’s just begging to be highlighted.
The Scarlet Brotherhood offers the reader an overview of the land and people under the control of the eponymous Scarlet Brotherhood, a standard bad guys faction in the world of Oerth/Greyhawk. The Olman, especially on the Amedio Jungles part, are presented as being on the decline, with their empire long collapsed, and only scattered tribes remaining. Of the seven great olman cities only two are still inhabited; one has a vampire dude as a ruler and his subjects are werebats and the other had its citizens turned into semi-feral werejaguars. Soooo, usual high-magic D&D nonsense I would say…
But, there’s levels to this shit, read on!
One of the now mostly abandonned city, Chetanicatla, was already in civil turmoil when it got struck hard by
covid a plague that eventually killed (after they turned crazy for a while, for good measure) most of its inhabitants.
[…] the three most powerful priest of the god Huhueteotl had protected themselves with repeated cure disease spells. However they neglected to cure a gibbering mouther that guarded their temple.
As a result, as these things usually goes :
The disease either caused a mutation or awakened a latent ability in the monster, giving it heightened intelligence and additional magical abilities. It promptly ate its former masters.
The super gibbering mouther lived happily ever after and self-reproduced like hell:
Its numerous offspring patrol the streets of Chetanicatla, eating any creature they catch, and the gibberspawn control the few people still living here [the poor souls].
For your edification, a gibberspawn is a tick-like (except with more eyes and mouths) parasite that can control its host while slowly draining its blood.