In a world I'm building, one of the most common creatures is the Limus genus. There are two species in this genus, the Limus silva and the Limus informis. The first is a standard slime that dwells in forests, swamps, and caves. The second is the mimic, a being that can change its color, shape, and texture to lure in prey and avoid predators. The idea I had for them was to be entirely made up of a gelatinous, acidic, cytoplasm-filled, mollusk capable of thought, sensing sound, and creating pseudopods, mimics are capable of changing color, shape, and texture as well. I am wondering if a creature like this could exist in a world similar to our own and what changes I would need to make it more realistic while keeping some core features.

The non-negotiable features are:

  • sight
  • thought
  • pseudopods
  • amorphous/gelatinous
  • texture changing for mimics

Other than that any features can be changed

  • $\begingroup$ An acidic organ capable of thought and senses ? How ? Assuming continuous thought, it should have considerable brain tissue somewhere.. thought requires neural pathways, interacting neuronal cells, dendrite-like structures. Your creature would not entirely consist of gelatinous substances.. also I wonder where the energy for that brain originates from. I think it will be difficult to get this through a "reality check". $\endgroup$
    – Goodies
    Jan 1, 2022 at 2:34
  • $\begingroup$ define "thought", it is a very vague term. $\endgroup$
    – John
    Mar 6, 2022 at 23:36
  • $\begingroup$ reality-check tag removed. It is not for asking "can X exist?" questions. As specified in the help center and tag wiki, it's purpose is to check a condition you supply against world rules you supply. Such a check against the "Real World" are off-topic because, frankly, if they could exist, they would. Asking what changes to the Real World would be necessary to allow your creatures to exist is a non-Reality Check question (but it's also the correct way to ask this kind of question). $\endgroup$
    – JBH
    Mar 7, 2022 at 0:07

3 Answers 3


Based on the characteristics you mentioned, I would say definitely yes, after all, an animal with similar "features" already exists in real life: Octopus.

  • sight:

An octopus has a full range of vision without the blindspot that humans have.

  • thought:

Octopuses meet every criteria for the definition of intelligence: they show a great flexibility in obtaining information (using several senses and learning socially), in processing it (through discriminative and conditional learning), in storing it (through long-term memory) and in applying it toward both predators and prey. Even its tentacles can "think" individually.

  • pseudopods

Well, although octopuses have tentacles, I wouldn't say this is a factor that would make the other features implausible.

  • amorphous/gelatinous

You can definitely say that octopuses have a somewhat amorphous body

  • texture changing for mimics

And here's the fun part: octopuses do have the camouflage feature, they even do it better than other animals that are better known for these characteristics (like chameleons).

  • 1
    $\begingroup$ Something of interest - Octopi are molluscs. So, the mimic-slime split could be made along the lines of which mollusc traits they embrace. Slimes, of course, would be slimy, secreting a layer of slippery protective goop outside their bodies like slugs. Mimics, on the other hand, could have functioning mantles, allowing them to build solid 'shells' as part of their camouflage. $\endgroup$
    – Bluejoy
    Mar 7, 2022 at 13:21

I don't think this kind of being could feasibly exist. First of all, a creature whose base state is gelatinous wouldn't be able to move or do much of anything really because you need some kind of muscle or something similar to move. It might be possible to create a gelatinous compound that could change its color, or possibly even texture without external interference, though I doubt it. A complex brain, or a brain at all is probably impossible. Sensory "organs" might be possible, but they wouldn't be organs, but maybe some kind of bacteria or compound sensitive to light, or temperature (in that case, it wouldn't really see, just know it is there, similar to how scorpions can sense light). However in order to process that information, it would need a brain, and as I mentioned before I doubt it could have one. Its mimic ability would also be impossible. As I said already, it wouldn't be able to move and thus couldn't mimic anything. Even if it could somehow move, its mimic abilities would be limited. I assume you're familiar with shapeshifters from Star Trek: Deep Space Nine. In DS9 you witness changelings mimicking various shapes, from small bird-like creatures to humans, but as we all know matter can't be created or destroyed, and such creature couldn't change its density, and thus couldn't just make itself denser when it doesn't need as much matter, and make itself less dense when it does.

But, you're creating a fictional/alternate world, and you don't need to follow our world's laws. You could always make up something in order to justify all its abilities.

In this answer, I assumed your creature would be something like a changeling from DS9.

  • 2
    $\begingroup$ "A creature whose base state is gelatinous wouldn't be able to move": slime molds beg to differ. See for example Physarum_polycephalum; or the most amazing Dictyostelium. $\endgroup$
    – AlexP
    Dec 31, 2021 at 23:25
  • $\begingroup$ @AlexP Well, when I was writing this answer I imagined something like a changeling from DS9. And that kind of creature couldn't move. If it could somehow increase its mass, and slowly transition from liquid to a more solid form, it could probably grow and "move'. For example, in DS9 changelings can make a hand from their liquid, and move it like it's a hand, which is impossible, there is nothing to maintain that form. I assume the mentioned creature wouldn't be as advanced, but still, I'm not sure it could transition from a blob to a larger animal, and maintain that form. $\endgroup$ Jan 1, 2022 at 1:10

No not with anything like earth life, every cell can't do everything, the best you could do is making them totipotent that is each cell is capable of changing in to another cell type.

slimes are close to possible, look at slime mold slugs, which can do most of what you want except see. the real problem is they all but helpless in a world with fully developed animals.

mimics are just impossible, the organisms that use complex changing camouflage are very intelligent, with extremely good eyes, there is no way to just program in that kind of camouflage you need active processing to recognize patterns and shapes and recreate them.


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