Drip-drop…drip-drop…drip-drop…
The sound of water falling from the tips of stalactites and into the lake was all that filled the cave. Keener ears could have heard the life buzzing around, but there were no such ears in this ecosystem.
It was a completely isolated cavity, a pocket inside the earth. The air was humid from a nearby magma chamber, an ample heat source, walls were covered in condensation, and a pale, glowing moss that had taken hold in the soft stone. Some small patches also blossomed on the ceiling, but those were the rare exception and destined to fall off eventually. The moss' roots simply didn't bury deep enough to reliably hold upside down.
Drip-drop…drip-drop…drip-drop…
That left the ceiling with ample room to grow more dripping stones. That should have provided the moss some different opportunity to cling on somewhere else, but when it reached a stalactite, the added weight would eventually cause them to break off. That would cause organic matter to fall into the water, giving the little fish and bacteria inside the lake a feast.
Drip-drop…drip-drop…drip-drop…
It was a minimal ecosystem, created randomly by volcanic activity shifting earth around dozens of years ago and trapping in it a multitude of species. Most of them hadn't survived, those that did adapted and created their own circle of life.
Moss grew. If there was too much moss, it fell into the lake. The fallen moss was eaten by the tiny organic lifeforms there, arranged in schools or swarms. They, or their predators, eventually died. Their remains floated to the narrow shore between walls and lake. There tiny eusocial insects, nesting in the moss, then picked them apart. Their defecations and corpses in turn were broken down by the moss and other bacteria. It was a stable system that could have lasted forever if left alone.
Drip-drop…drip-drop…drip-drop…drip…Falling…
It was a chance that was so infinitesimal, so close to zero, it should have been an impossibility. Maybe it was a powerful god that twisted the world a little bit. Maybe it was just a random probability of natural movement. Maybe the actions of an insane magician somewhere had caused the magical veins of the world to shift for just a moment. Maybe it was an insane magician battling a powerful god at the advent of a natural shift in the natural veins of magic. Maybe it was none of those things at all.
Fact was, that just one drop of water fell past, crossing invisible streams of different elemental properties at exactly the right moment. A tiny spark, nothing more than a single ember raising from a campfire, flared up in the cave. Then it was gone again. In that tiny moment, the minerals carried within that miniscule bit of water changed and rearranged themselves in the shape of a hardened core, what had been water became part of another liquid, one more viscous and able to stay as one.
With a drop, the new-born creature fell into the water. The very first thought crossed through the being's mind and it was a majorly confused one. It had been suddenly thrown into the world at a part where there was not but sentience while itself having full sapience. With no idea what to do with it.
It sunk to the ground, wondering about that very thing. Without any language it couldn't have known how to speak, its thoughts were an assembly of feelings, shapes and colours.
It was a slime, a monster known in this and other connected worlds, as a common life form with little power that digested things smaller than itself. A simple being indeed, consisting of two parts: the name giving, usually acidic jelly and a nucleus. Basically, nothing more than an oversized bacterium.
It settled on the bottom of the lake and just sat there. Sat there for a long time, learning how to sense and still wondering. Slimes didn't have eyes or ears or any other perceiving organs. Lesser slimes could perceive the world through vibrations only. Their larger, more powerful cousins could also sense from the magical flow that permeated everything. At that point, it was as if they had sight, smell and hearing but better, only limited by range.
It wasn't a lesser slime, it was something with an ability hidden deep in its nucleus. It knew that. It wasn't quite sure how it knew that, or what exactly it was that it knew, but it knew that it knew that it should know. It was a memory not yet made, but one to be rediscovered. It was to be one of the truly powerful creatures of the Leaves.
Potentially.
For now, it was stuck with only sensing vibrations like the lowest of its kin.
A feeling of emptiness set in, an urgent one – hunger. Even as a lifeform primarily based on water, the tiny slime had to eat. It tried to move, extending parts of it forward and pulling the rest behind. It was slow at first, but soon the movement became routinized, and it slugged at a steady pace. However, it still wasn't fast. For sure, not fast enough to catch anything. It was only the fact that it was nearly indistinguishable from the surrounding water that let it approach its prey.
That first meal was to be an elongated insect, judging by the feeling of the hard surface moving through the water. It was busy scratching some gunk off a nearby pebble with its pincers and getting whatever nutrition it still could. It was working quickly, with high energy and vitality. A healthy snack, despite the insect's own diet, that much was certain.
As careful as the slime could, trusting entirely in the innate hunting instinct it had, it stretched around its prey. For as long as the translucent predator remained unnoticed, it should take the opportunity to cut off as many paths of flight as possible. All that could give it away was moving too fast and giving its presence away to the prey through the sudden movement of water. Even an animal with a basically non-existent brain would instinctively flee if it sensed a sudden change going on around it.
The insect noticed that something was up at the last moment. The outstretched jelly rushed towards the prey and missed. Missed by such a wide margin that the slime stopped moving in confusion. Sensing for the insect that should have been there, that something should have been satiating the hunger right now, it sat still. It found a tunnel of vibrations from something moving at an immense speed, the settling insect by the end of it.
It seemed these little prey animals had some sort of trick to dash from potential dangers. While frustrating, that also taught the slime that there was something else hunting in these waters. Otherwise, there was no reason for them to have that skill.
The slime sensed for an easier prey and eventually found one of those insects feeding nearby. Extremely close, to be exact, as the slime wouldn't have been able to really sense it otherwise. Feeling the tapping of the cleaning insect's tiny feet, the slime knew it to be missing one of its six legs. It also worked with little energy, compared to the earlier specimen. This one was either old, or crippled, or both. Whatever it was, this ought to be easier.
The slime bridged the little distance between them carefully. What wasn't even a step for a wolf was a minute-long stalking path for the slime. Once it was in range, it repeated the earlier strategy and then attacked.
This weaker insect did not get away, the front half of its body getting immediately surrounded by the slime. The stilt-like legs of the creature tried to dig it out, but it was only treading inside water, tiring it out rather than removing it. Waving desperately with its long behind uselessly soon ceased, as the insect completely exhausted itself.
The slime soon covered its entire surface, and then the newly successful hunter in these waters sat there digesting. From the feel of it, this one hunt would feed it for quite a while, but aside from the satisfaction there was something different. As more and more flesh of the insect inside it dissolved, the slime understood how all of it worked. How tissue was connected to the exoskeleton, how an immense lash of that long tail allowed it to dart away, how the legs could move. Even more than that, it could reconstruct parts of it that it wanted.
First, the slime grew the legs, sick of crawling around. Six healthy legs with a carapace. Those allowed for easier movement over the floor. Then it tried to grow the elongated tail. As the slime attempted to do so, the legs disappeared again. It seemed there was only so many stolen attributes it could maintain at one time and growing them took quite some energy. It was already hungry again.
It was time to hunt for some more food and tools. The goal: drip-feeding to become this biomes apex predator, thus securing its own existence. Then? Well, the slime didn't know. Hopefully something new would be beyond this pond and the cave surrounding it.