I am planning on making a new species based on octopus and humans. Human in skeletal structure, Octopus flexibility. I am thinking of calling them octopeople.

As far as flexibility, I am thinking of having muscles in the arms attaching directly to muscles without any bones. Not sure if I should have human hands with bones or 5 smaller tentacles attached to the arms as fingers.

But the more important question is how to protect organs. If the muscles are attached to muscles for flexibility that is 1 thing but human organ systems which need protection is another.

I can see how all of these organs would need some kind of protection:

  • Brain
  • Heart
  • Trachea
  • Lungs
  • GI tract
  • Liver
  • Gall bladder
  • Pancreas
  • Kidneys
  • Spleen
  • Bladder
  • Prostate(males)
  • Testes(males)
  • Uterus(females)
  • Ovaries(females)

I mean squeezing through an area no bigger than your eye or even squeezing through an area no bigger than your arm would cause death from external pressure if humans were even able to do it. The reasons babies don't die from pressure in the birth canal is their skeleton consisting of a significant amount of cartilage, the elasticity of the birth canal, the fontanelles, and the cardinal movements of labor.

But is cartilage going to be sufficient for throat and torso protection or should there be fat around the organs to spread the pressure to not have organ failure from compression? If neither works then how could organ failure from compression be prevented?

  • 2
    $\begingroup$ Human in the skeletal structure and without any bones. <<scratches his head>> $\endgroup$
    – L.Dutch
    Commented Mar 24, 2018 at 3:57
  • $\begingroup$ The without any bones is referring to the arms. The Human in skeletal structure is referring to areas other than the arms. And just because there are no bones does not mean that there would be no joints. Cartilage could be the material that is in the joints and skeletal structure. That technically means no bones but still having human skeletal structure. $\endgroup$
    – Caters
    Commented Mar 24, 2018 at 4:31

5 Answers 5


Don't protect the organs

...let them be flexible instead.

Octopii have gotten along without rigid components for longer than the dinosaurs. Clearly, their biology and environment will support that kind of morphology and physiology. If we are designing human like characteristics onto an octopus framework, then a lot of stuff will have to go.

There's two approaches to protection, be so hard that no attack can penetrate or be so flexible that you just bend out of the way. Humans are a mix of the two, trending towards hard. Octopii are all the way on the flexible end. To make octopeople, you'll have to remove the elements of human anatomy that prevent a human from being an octopus. This means bones and teeth will be removed in favor of a hard beak.

Most human organs are pretty squishy already. Repurposing the octopii organs or adapting the human organs for a much squishier environment would probably work just fine.


Please, PLEASE, excuse the crude artwork (I'm almost embarrassed to put it put up but this is all my work computer can do LOL). The second artwork below is ok.

The torso would have a rib cage. It would be the only part of the body with a solid skeleton. And it would made of cartilage which is more flexible than bone.

But be careful, those can still snap. So you still don't want your octo-humanoid squeezing through just any space. My cats are pretty big and can still squeeze through the smallest areas, but I wouldn't want them pushing their luck.

The rest of the body, even the head, could be malleable just like the body of an octopus.

enter image description here

Doesn't he look happy to be alive? Cheers!

EDIT: I just wanted to come back and offer some better looking artwork. Your octo-humanoids might look like this:

enter image description here

Just imagine them with longer arms.


Edit: A thought occurred to me. I had assumed that this guy was intended to be an underwater species. I'm not so sure he could live on land. Even with the rib cage most of his body would still be too malleable to run around on land, even with powerful muscles.


  • $\begingroup$ But how would the brain be protected without any bones? Lots of fat to spread the pressure I suppose? $\endgroup$
    – Caters
    Commented Mar 31, 2018 at 21:00
  • 1
    $\begingroup$ @Caters, you already have the best example of what you're looking for: the octopus themselves. Find out how they do it and go from there. My solution would be not to have squeeze through anything that would be unreasonable. Good luck. $\endgroup$
    – Len
    Commented Apr 2, 2018 at 4:40

You simply can't build a creature like this that will work, the human breathing system is mammalian, and the mammalian breathing system has to have a rigid rib cage to generate negative pressure to inflate the lungs. so your creature cannot breath and that is just once function of one organ, before you get ot the issue of holding itself up or eating.

  • $\begingroup$ Wouldn't cartilage provide that rigidity while being flexible? I mean rigid does not mean not flexible. Even bone, which is rigid is still flexible to an extent. $\endgroup$
    – Caters
    Commented Mar 24, 2018 at 4:35
  • $\begingroup$ no unossified cartilage is not even close to rigid enough, and ossified cartilage is called bone. $\endgroup$
    – John
    Commented Mar 24, 2018 at 21:26

Maybe you could use the "squishiness" of octopuses combined with a fantasy version of an exoskeleton (skeletal system on the outside, like bugs). By making the organs elastic and recoverably deformable (turning back to their original shape afterwards) and using something like a type of liquid that either hardens or temporarily hardens the skin and/or bones.

This could make it possible for these people to both go through small holes and have sturdiness for movement and/or protection.

I don't know of any animal that does this though. (I don't know how realistic this is supposed to be.) I do know however that fleas use a fluid for their high jumping ability and if we look at blood clotting this can harden and can biologically be broken down. If you then imagine tube-like structures with a valve and another valve that connects with an organ that causes blood to rapidly clot. Then when it fills with blood and the first valve closes and the second valve opens, releasing the fluid hardening the blood, you have more sturdiness. I would imagine that this would be similar to those balloon figures. I think this would however increase the volume, like when you blow up a balloon, so you would need pretty flexible skin.

For harder surfaces, pack them with lots of other structures like this that are perhaps a bit smaller and packed really really tightly together with higher internal pressure. Maybe make it analogous to how bones and tight, hard muscles work with us. Bones would be bone big hardened thing, while tight, hardened muscles are lots of small long thingies packed incredibly tightly together, which can sometimes get even harder than bones.

  • $\begingroup$ As part of my edit, corrected "endoskeleton" (the kind of skeleton we have) for "exoskeleton" (the kind of skeleton insects have). If that's incorrect, feel free to edit it back, but it seemed to be what was being implied. $\endgroup$
    – jdunlop
    Commented Oct 10, 2019 at 21:02
  • $\begingroup$ Yeah, that's what I meant. $\endgroup$ Commented Oct 11, 2019 at 6:35

An interesting premise: what makes a human human, and not an octopus? What is actually the main difference?

If you want to combine the two - perhaps think of a human brain in an octopus body - besides lungs octopuses have all the organs that you have listed.

You mentioned though the octopus would have human skeletal structure - there is no need for this. Have a look at how species evolve.

We developed bones from essentially fish, which later became amphibious, and in order to more efficiently walk (or rather waddle) on land fins became arms and legs, lungs developed with ribcages, spines became harder. Soon we had hipbones to run faster and this then developed into us.

Would your creatures live underwater still? If so no need for the bones, they would be quite an impediment. But if the octopeople are on land - it makes sense a rigid structure is needed to stop us from flopping around, but then do we need 8 arms? You might find ironically that evolutionarily the Octopeople then end up just being like us.


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