So, in my story there is a species of aliens, called the Ko’dor. The Ko’dor are a species of shape-shifters, who can change their forms at will. Naturally, they are four-eyed, green octopus like creatures. But, they have the ability to morph and change to human, or any other species's, shape. But, to the Ko’dor, shape-shifting takes a lot of muscle bending and skin folding.

A Ko’dor spy has just entered your spaceship. The Ko’dor is unnoticed at first, but once he accidentally spills over a salt tin in his quarters, he dies. I can’t let my main characters know the spy is there yet, so the Ko’dor has to stay in his human form, even while dead.

Since muscles normally relax after death, why might Ko’dor biology allow them to stay in shapeshifted form, even while dead?

  • 2
    $\begingroup$ Ko’dor biology works differently than Earth biology; one way this is manifested is that the default muscle state iscontraction. $\endgroup$ – RonJohn Oct 8 '18 at 22:36
  • $\begingroup$ an extreme version of rigor mortis maybe? $\endgroup$ – BevynQ Oct 9 '18 at 4:26

Your Ko'dor aliens need a voluntary physical effort to change shape. If they don´t activate the muscles and the skin to return to their original shape, the process won´t happen. That is an evolutionary advantage, because if they are left unconscious or if they sleep, they mantain their current modified shape. The only way to know they are not humans is by means of an X-Ray scan, a blood sample, or a trained dog (the dog will immediately sense the different smell).

  • $\begingroup$ What are some evolutionary reasons why the Ko’dor would develop this ability? I still need some help in that $\endgroup$ – DT Cooper Oct 9 '18 at 0:24
  • $\begingroup$ @RobertPaul That sounds like it would be better asked in a separate question. $\endgroup$ – Sydney Sleeper Oct 9 '18 at 1:23
  • 3
    $\begingroup$ I suppose that, after death, there is no longer an evolutionary advantage in anything. But if they shape-shift to fit into a tight space, for instance, and they lose consciousness, they would no longer 'fit' and probably die. Those organisms that stay in the same shape, even when unconscious, have a better survival rate than those who return to their natural state and thus negate the safety factor that they had when they shape-shifted to avoid a hazard in the first place. $\endgroup$ – Justin Thyme Oct 9 '18 at 1:25
  • 1
    $\begingroup$ @RobertPaul consider how this ability might've developed. Turning back into a food item of the species whose nest you've infiltrated might be hazardous to your health. Perhaps they need to stick around until the eggs are laid though, and have to rest overnight? $\endgroup$ – Roland Heath Oct 9 '18 at 2:39
  • 1
    $\begingroup$ Simple energetics would make this the most advantageous way to shapeshift. One time expenditure of energy rather than constant expenditure makes this the cheaper option to maintain. $\endgroup$ – Joe Bloggs Oct 9 '18 at 7:01

Rigor mortise sets in immediately with this alien biology.

The muscles loosening up is a uniquely earth-bound biological mechanism. No need to posit that it HAS to happen with aliens. Their muscles could immediately stiffen, due to the enzymes that allow the extreme flexibility of the muscles no longer being effective in death. The enzymes are no longer biologically active, the muscles immediately freeze up.

Since I assume the Ko'dor have no bones, I can't see any particular necessity for them to return to their 'natural' shape.


Ko’dor's body is like a piece of paper, and their assumed forms are like origami figures. Even after they die, they stay in their latest shape.

enter image description here

  • $\begingroup$ How does this relate to a shapeshifting creature using the mechanisms the OP has described? The OP describes use of muscles and skin folds, their skin is not paper. $\endgroup$ – John Locke Oct 9 '18 at 1:45
  • $\begingroup$ Surely origami & paper are analogies for the Kod'ors' muscular tissues? The external process appears somewhat origamilike, but the actual work is done by muscles & connective tissues & probably some cellular level fluid pumps & pigment arrays. $\endgroup$ – elemtilas Oct 9 '18 at 2:07
  • $\begingroup$ @John Locke - Carlos Zamora's answer offers more scientific details to that process without superfluous metaphors :) $\endgroup$ – Alexander Oct 9 '18 at 7:24
  • $\begingroup$ @elemtilas Then the answer should explain those processes instead of giving an analogy. $\endgroup$ – John Locke Oct 9 '18 at 10:49

Why not have no one see the corpse? Your spaceship just stayed on a planet where a contagious disease has spread. When the alien dies, his health monitor detects the death, but is unable to determine what caused it. So the disease is suspected, the corpse is handled by robots, frozen and send in the morgue, in an airtight coffin, to be autopsied when the spaceship reaches the next planet. The robots may detect that the corpse is not human, but they're not programmed to alert the crew in this situation.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.