A short man in a lab coat opens a file and starts reading some informations, while filling you in on the creature
Name: Filed as "Number 8008: Saylar"
Appearance: Irrelevant. Or blobesque.
Biology: Saylar is a mass. A mass of smaller masses. Composed mainly of muscle tissue, these ameobae-like components have the ability to replicate themselves. In normal condition, this doesn't change anything, as it barely offsets the loss of elements due to the slime's normal activity, like movement. It also sometimes consume parts of itself to produce energy. So the more tired it is, the smaller it gets.
However, in the right conditions, Saylar will stop moving and start replicating at a higher rate, efficiently increasing his mass.
Though lacking a proper brain, each and every cell-like component of this blob has a basic instinct, and a hive-mind ability. They transmit basic information through electrical discharges, in a way similar to a nervous system. If Saylar weighs more than about ten kilos, it has a basic, animalistic intelligence. Once over thirty kilos, it can reflect like an average human being. It is theorized that sufficient mass would make it more efficient than a computer. That would, however, require a lot more replicating than the scientists dared test in labs. Because of its internal communication system, the curve of intelligence/mass is logarithmic.
The "right conditions" are still unlisted, but it involves warmth, humidity and a calorie source. It is theorized that its instinct to instigate parts of itself inside living beings is related to that.
When it's not reproducing itself, its ameobae-like components can reproduce analyzed fluids. If the liquid has been contained inside the mass for long enough, the cells are able to produce it, at the cost of a good amount of calorie. Some of the cells act as "fluid memory", storing the substance's composition for future use. Theoretically, Saylar could reproduce any human bodily fluid, but its memory is nearly blank at the moment.
Seemingly, this blob doesn't possess eyes, ears, or other sensory abilities. It does, however, have an incredible sense of touch. It navigates by sensing vibrations, mostly sound. This explains why it makes a little sploshing noise when moving, because there is no other reason for it to intentionally make any sound. However, its basics instincts seem to be to cover noise sources. It has been observed when it lunged toward an observer's mouth to get her to stop speaking. To this day, we are not sure part of Saylar is not still in her bowels.
Behavior: The most basic instinct of this beast is to reproduce itself. While a climate-controlled terrarium has done the trick, it seems to prefer live hosts. Let me explain.
As I said, this creature can replicate its core self -AKA the first ameobae-like particle- in the right conditions. It seeks warmth, humidity, and a calorie source. The human body seems to be the perfect place to get all this. However, and call it a conservation instinct, it will never deposit more than a fraction of its mass in the same being, in case the... Ah... "incubator" gets compromised.
Once inside a host, it starts replicating itself, absorbing and dissolving its surrounding to produce energy. Its sense of touch allows it to feel around itself to differentiate body parts from unnecessary items, like food. As an experiment, we placed it in a container made of synthetic skin, and it seemed to absorb most of it, to a certain point. It never "ate" a hole in the bag, and it kept it thick enough to hold it mass. Also, after a few hours, we noticed some drooping on the skin bag. Once emptied and analyzed, we came to the conclusion that Saylar can naturally produce an enzyme that will adapt to the organic tissues and meld into it to give it more elasticity.
Once it deems the host "full", the newly produced slime will wriggle out of the body to find the main host, completing the objective to making itself bigger. It is very likely to leave some behind to keep the repdocuing process going.
Once a host has been "secured", the slime might want to keep it in one place, and keep it alive. It will attempt to feed its host with one of the fluids it has analyzed.
There's a footnote saying that its internal communication system makes it particularly sensible to electricity-based stunners, like a clasic taser.
Oviposition: Yes. Sort of.
Pregnancy: Yes. Sort of.
Copious amounts of cum: Yes. Once said cum is analyzed. Though it will be in a feeding attempt.
Pheromones/Aphrodisiac: Yes, once the aphrodisiac is reproduced. Can be mixed with the aforementionned cum.