Probably the carrion-eaters would swarm it and form a complex localized ecosystem that could be sustainable for decades.
Or, to put it another way, people would form a city around it in an attempt to exploit it for their own financial gain.
It would start with someone wanting to know more about it and looking to hire people to explore it. Then, someone dumb enough would take the job. Assuming they survived, tales and rumors of their discovery would spread, then more would show up. Knowing these folk would need basic necessities at hand, caravans would arrive to feed off the discovery second hand. Then the families arrive. At some point along the line, the generic mass of people organize and a town forms.
They'd probably give it some dumb name too, like...
GodfallThe event occurred one cold, snow covered, winter evening in the Dalr valley of the Fjell mountains. Without warning the quiet valley erupted in madness as the beast crashed it's way into reality, fracturing the laws of physics and causality as it did. It thrashed and rived for days, tearing up the surrounding area, until finally dying.
While the noise was maddening, the deafening silence that followed was perhaps even worse. The noise, caused by reality attempting to reject the presence of the Beast, resounded with the pure essence of rebellion and chaos. The silence, however, echoed with submission; a reality broken and beaten with no fight left to ward off the intrusive presence.
To the untrained eye (that is one not forced to look upon the Beast day in and day out) the Beast is hard sight to behold, its very presence an offence to any sense held by a creature of this reality. A pallid skinned creature, appearing as a slain cross between a blobfish, harvestman, and an axoloti suffering from sever genetic drift, it lays partly upon the surface, and partly fused with the rocks of the mountain range itself.
If one were to find a map of the area from three hundred years ago, they would probably note a vast dwarven kingdom that inhabited the mountain region, though somehow forgotten to modern memory. Maps drafted three hundred years in future, however, show an ancient dwarven kingdom, absent of any notation regarding Godfall.
The Surrounding AreaJust getting to Godfall is a pain in the ass, as a metaphysical crater was left from the impact. Some of the hazards include:
Midnight Woods - A region of forest populated by blacken gnarled trees that exist in a constant midnight. This ain't a metaphor - no matter the time of day outside, within the match it is constantly night, though the night sky visible through the trees offers no known constellations. The woods actively offer resistance to any who enter, the trees themselves striking out.
The Standing Men - A field of standing figures, dressed in attire from various cultures throughout the ages. Though scattered throughout the field, any who enter the field freeze permanently. There's at least one figure frozen midair with a terrified look on his face. A few have crossbow bolts pointed towards their head. While no one has figured this out, the figures are locked in a temporal field. For them time passes normally, while outside they move at one hundred thousandths of normal speed. A safe path through does exist, for those clever enough to find it.
Crystalline Pass - A passage between the mountains where every exposed rock and plant has been transmuted into crystals, with mirror like surfaces. Upon closer investigation, however, the crystals do not reflect the observer, but a possible version of the observer. Whether these alternatives are from an alternate reality or timeline is uncertain. Take care when passing through this region, however, as it has been rumored that one can become confused in the perfect reflects and, sometimes, the reflections will walk out, leaving the original trapped.
The Valley of Glass - Some places it rains water. Here it rains glass. Don't get caught in the rain.
The Outer CityThe Outer City is similar to any city with a colossal carcass of an extra-dimensional being rotting in the center of it. General stores, blacksmith, tannery, game halls, whore houses, iron-barred-window asylums, flesh mines, sinister looking wizard tower that echos strange noises in the dead of night. You know, the usual.
Yare's Yaren - A tanner who cures their leather in the strange liquids that seep forth from the rotting creature. Items made from this process typically carry unique properties, depending on the solution it was cured in.
The Flesh Mines - Exactly what they sound like. Though only marginally less dangerous than the mines of the Inner City, the exterior Maggot Halls employ more of the populous through the simple fact that workers get to see the sun at least once a day. While some of their product is sold as food within the town, the majority of their harvest is sold directly to the Wizard Tower.
Wizard Tower - More of a collection of towers and joining wall around a central pit, than a traditional single tower, it was the very first building built in the town. Strange glowing can be seen in the windows at night and horrifying sounds echo from within. None of its members show themselves in public, and rarely speak of their intentions. Rumors abound of flesh gollems that serve the wizards and of the vats they're grown in. These rumors are true. They are entirely true. What the rumors don't speak of are the homeless and lower class peasants that are pulled off the street and thrown into said vats to serve as stock to bound with the added beast flesh.
The Inner CityThis part of the city is built within the creature itself, specifically the part that is assumed (and hoped) to be it's mouth orifice. First thing new arrivals notice is that the creature appears to be larger on the inside than the outside. Next, which they may learn the hard way, is that spatial based reasoning and perception doesn't work exactly the same as it does in the outside world. Alleys that one can walk hundreds of times can suddenly lead to a different location, or deep into the Belly, with no warning. Even just entering the Inner City carries a chance of becoming lost. At some point some genius installed a rope for people to follow from the Outer to the Inner, after paying the toll of course, but every so often (say 1 in 20) not even that will lead to where it is suppose to.
Here you'll find the mining offices, the distilling factories, and various other processing plants, along with the worker barracks and company store. Raw materials from the Belly are brought here for processing before being shipped out to the Outer City.
The Belly of the BeastSome of the more sought after materials are drawn from here. Trouble is, the deeper in you go, the more standard rules of reality stop applying. Fleshy tunnels give away to stone hallways, whose walls still carve as meat. Euclidean space dissolves away into non-Euclidean expanses. Time rethinks the whole "linear" thing, and explores other options. Wizards mutter something about metaphors being made reality, but no one really pays them mind. Not as long as their gold is good, at least.
Here's a peek at some of the creatures (antibodies?) lurking within:
The Flat Ones - "Humanoid" looking creatures that lack a third dimension and, as such, are often mistaken for paintings and graffiti within the strange hallways, though they appear invisible when "seen" from their missing dimension. Anyone killed by these things does not die, but rather they have one of their three dimensions sapped from them, joining their ranks and becoming trapped in a never dying, never living two dimensional hell.
The Lost Boys - Any semi-industrial town is bound to generate at least a few orphans. It's just a natural occurrence. So, what do you do with them all? Stick them in a group home and hope some soft-hearted person will take them away? No, obviously not. You employ them with a promise of hot meals, tie a rope around them, give them a sack and send them into the Belly in hopes their tiny hands grab something of value. Sometimes, though, they don't come back.
Cephalocells - Imagine an octopus. Now, remove everything that makes it an octopus. Then add a beak full of barbs, and the ability to freely move in all three dimensions. Also, an eye on the end of each tentacle that is capable of unleashing a variety of awful magical effects upon reality. Often found around neon green sacks of neutrophil, from which they're being expelled.
People of GodfallBeyond the usual collection of townsfolk (merchants, craftsmen, prostitutes, etc) there are a few assorted people unique to Godfall:
Though it would serve as solid proof their god exists, no legitimate cleric will claim it, as it also proves their god is dead. Several have jumped at the chance to claim it as an enemy of their god, to flaunt the corpse of a vanquished foe and the victory of the mighty god they follow. There are those, however, that do take the creature as divine, and see the rotting carcass as a chance at, or at least a vision into, something beyond. Going along a vague train of thought related to "you are what you eat", cults have sprung up around consumption of the humors - or what is thought to be the beast's humors - in order to harvest some of the dwendling divinity. You can usually identify these people by their mutated visage and the occasional painful seizures that take them as four dimensional shapes boil over them.
No decent religion is without a counter part for which they can claim is sinful and damnable. This is where the Flesh Shamans come in for the Humor Cults. Where the Cults consume the humors, the Flesh Shamans consume, believe it or not, the Flesh of the creature, seeking the divinity that they insist is in the meat of the creature. They're notable by their rolling mounds of mutated flesh that doesn't seem to hinder their dexterity.
Madmen who hide their insanity through the thinly veiled excuse of arcane eccentricities, they seek to learn all they can, and more, of the beast at the center of the city. Some seek to reanimate the flesh, some seek to call others like it from beyond reality. The wizards are easily identifiable as none leave the tower without donning animal masks and heavy, form hiding robes.