Mystery Flesh Pit National Park
The Mystery Flesh Pit National Park is an enormous superorganism burrowed below ground in Texas from an ARG of the same name. The ARG has a huge amount of worldbuilding, and would serve as a good idea of the bad things that could happen if humanity, especially corporations, tried to take advantage of a massive Lovecraftian entity, particularly useful for games like Delta Green or Masque of the Red Death. The Mystery Flesh Pit is also referred to as the Permian Superorganism, and is so large it has its own ecosystems of parasites within it.
Native Lifeforms within the Permian Superorganism
File:MusteryFleshPitFauna.jpg Many strange and often deadly species have evolved over the millions of years within the superorganism, new evolutions of a parasitic nature which just as often tend to prey upon one another as the flesh of the massive beast they call home. Some rumors even float about of a race of Abhuman adapted to living within the Pit called The Marrow Folk!
Connection to /tg/
Besides the potential as a setting for a Roleplaying game like Call of Cthulhu, Delta Green or Masque of the Red Death, the parasitic lifeforms within the superorganism itself can serve as inspiration for lifeforms in settings featuring massive, living landscapes. If you want to homebrew a world like The Writhing World, Oliensis, or Fleshworld, the dinosaur-sized (and possibly descended) parasites of the inner depths of the Flesh Pit could give you great inspiration!