A week ago, the first city was plagued with a sickness, it was quickly shown to not be a random event as quickly after, other cities were infected, the sickness didn't have any symptoms that seemed strange, vomiting, headache, weakened state, nothing out of the ordinary, except that people died from it, rare and few were the ones able to survive an infection for the sickness.
It was quickly discovered after investigation that it wasn't a sickness at all but poisoning, finding the source of the poison was easy, all of the plagued cities had one thing in common, their water came from the same river, a long and large river that had been perfectly good to consume for centuries had suddenly turned poisonous and even venomous as it seemed to infect people through wounds as well.
As was commonly done everywhere, some soldiers were dispatched to investigate the surroundings of the river but they found nothing and risks of war forced the crown to call upon all of its soldiers, leaving only the adventurers per usual.
They did the same as the soldiers but for a much more extended period of time, scouting the surroundings of the rivers and inspecting even further away, in a certain area, where the river traversed through a fetid stench could be smelled in the air, the strength of the stench was enough to make anyone gag on reflex and even push some to straight up puke upon smelling it.
It was absolutely rancid and many, even though it definitely was a lead toward the source of the poisoning, decided to leave, unable to support the smell even through a piece of cloth.
Only a few teams choose to keep on investigating the reeking area and today, only one was currently on site, simply oberving the zone from afar while sittingat their camp, they had been doing this for a while and were starting to believe nothing would happen but this day, a few hours after they had all woken up, a most bizarre figure appeared from behind a tree, grey and palish, tall and lanky, a lack of facial features, claws on each of its five fingers, it was a monster for sure.
It slowly made its way to the river, leaning over the water for a minute before suddenly, its head opened up, revealing that the flesh on the inside was in complete putrefaction, the smell suddenly struck them as it opened it, revealing that it was indeed, the one responsible for the smell, it moved its head back and forth for a bit, making a movement they had grown accustomed to since the discovery of this area.
With a nasty, guttural sound it suddenly expulsed a suspiciously high amount of liquid rot which melded in the river, visually, it was like the river was perfectly fine.
The monster slowly walked to where it came from, suffering through the instense smell, the adventurers gave chase to try and find its hideout, they had searched these parts a number of times and had never found anything, making them a bit unnerved that such a monster had been able to slip right under their vigilance.
They followed it from a distance and after a while it just hopped straight into what had appeared to be a puddle of mud, completely sinking in, having collected quite a bit of information and lacking the wish to follow that thing in its puddle, they contacted other adventurers and set up an ambush for the next time it would come out.
They placed a cage around the puddle and prepared lots of fire type attacks, as was commonly known, undead monsters were susceptible to fire, especially the fleshy ones and it appeared that it was of that category.
The first time it came out, fire proved to not be effective at all, it took the attacks like a champ and sent out its pressurised puke to stop other attacks, a few dies and the monster dragged two adventurers with it in its puddle, namely the priestess and tank of a group.
After that, it stayed inside of its puddle for even longer, it hadn't been hurt the first time so it probably wasn't fearful of them, so what was it doing?
After that, it multiplied the exits, always dragging people with it, seeing that they were no match, the adventurers had already given up, no on wanted to learn what happened after it dragged you to its muddy domain.
There was also the fact that the monster had appeared more and more disastisfied as time went on and had started aiming to drag more and more females specifically, this scared them even more and it was the end of their attempt at an ambush, they all disbanded and left, leaving the poisoner by itself.
Despite the clear failure of their operation, after a few months, the water stopped being poisoned, it was now safe again to drink water from it, a few people went to investigate the monster and one even went as far as to enter the puddle of mud, only to come out with a paled face.
The monster was nowhere to be seen, it must have left the area but the person reported the horrible sights they had had to face.
In one room, a large pile of rot could be found and as could be guessed by the not so far carcasses from it, it seemed like a reserve of the monster's 'puke' but this wasn't the worst, in another room, isolated from the others, arranged in lines, were the waist of humans, they were rotting and hardly identifiable due to only the waist and a bit of the leg being present but judging from the spunk that covered all of them and their rough appearance, it was clear what it had been trying to do.
After these report, no one dared to go in, no one around was curious enough to go take a look at the morbid spectacle.
The monster's presence could still be traced as various places so their waters poisoned, each time, the symptoms of it would get more and more severe, until the stench could be smelled from kilometers away.
When the monster decided to go for a swim in the ocean, this was when its true dangerosity was understood but it was too late.