So for a story I'm working on I thought of a forest-dwelling predator (see the image for a design) which has a skin very sensitive to light (not in a painful way, just that it notices differences in intensity and shadow), and an organ at the end of its tail which releases a special airborne toxin, if you will, which numbs the senses of animals/prey around it (those senses being sight, hearing and smell in this case).

The idea of its light-sensitive skin was: the predator hunts when the sun is low and there are lots of shadows in the forest (lots of patches of light and dark). Because it moves very slowly, and its skin can sense which parts of its body are covered in light and which parts covered by shadow, its pigment can sort of "move along" with the detected light and shadow, as to blend in with the environment.

Seeing as this would probably still be visible for a 'sober' prey, the airborne chemicals released from the organ numb the senses in a way that such irregularities in the background are less noticeable or fade away. The prey would become sluggish and far less aware of its surroundings.

So I guess I have 2 questions concerning the same beast:

Is an organ releasing intoxicating chemicals into the air somewhat realistic?

And: is the concept of pseudo-camouflage described above in any way viable or imaginable? I find it sort of hard to describe the process in a clear way, but I have quite a specific vision for it.

Please note that the world this creature inhabits is also filled by magic forces which can influence the way nature and evolution work. I don't want this to affect every animal or creature in there, but I want to keep it in mind as a sort of alibi for explanation.

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  • $\begingroup$ Does that creature have six legs? That's certainly not impossible, but you might want to give some thought to how it evolved on a branch different from that of most larger animals (which are quadruped). $\endgroup$
    – user
    Jul 19, 2017 at 12:24
  • $\begingroup$ Also, what's that thing at the end of its tail? If it's something similar to the clubbed tail of the ankylosaurus, keep in mind that that makes more sense for a prey species that needs to defend itself, than a predator. Remember that at least absent magic, every part of the animal needs to at least not hinder the animal more than it helps; if there is no survival advantage to having e.g. a tail club, then over time it will grow smaller and eventually disappear (more or less). $\endgroup$
    – user
    Jul 19, 2017 at 12:28
  • $\begingroup$ In the universe of my world I also envision European-like dragons to have existed (with four legs and two wings. I suppose I would argue that an ancestor of those dragons, as well as this creature, at some point in evolution developed an extra pair of arms/legs. $\endgroup$ Jul 20, 2017 at 0:17
  • $\begingroup$ To answer your second question, that thing on its tail is the organ with which it spreads the toxin (as indicated in my description. I guess the form of its tail is somewhat for aesthetic purposes, but perhaps I could argue that it somehow aids in keeping balance. And I think I'm willing to take some small liberties in the design of creatures like these, since I don't envision playing them a major role in the story, and I don't feel the need to use hard science in all designs. Thanks for the comment. $\endgroup$ Jul 20, 2017 at 0:24

3 Answers 3


Diffusing chemicals through air has some inconvenience:

  • it dilutes the concentration aways from the source (your predator moves slowly, and it is therefore highly desiderable that its toxin begins to affect the prey from a distance)
  • it's subject to wind direction (any upstream prey will be safe)
  • it may be less effective during rain
  • forest environment can hinder toxin diffusion

It would be better if the organ releasing chemical would act as defensive medium: it becomes more effective the closer the potential predator is, allowing a swift escape.

It would be even better if the animal could target, for example by spraying or spitting, the toxin toward the prey/predator.

Regarding the camouflage it resembles what octopus already does. So it is in principle possible.

  • 1
    $\begingroup$ "Pray" is something you do to a deity. "Prey" is what something might be to a predator. $\endgroup$
    – user
    Jul 19, 2017 at 12:21
  • $\begingroup$ Thanks for those bulletpoints, I didn't really think about that. I am willing to take some liberties in these designs, but should I want to change it I could indeed have the creature spray the toxin on a prey instead of spreading it into the environment. $\endgroup$ Jul 20, 2017 at 0:27

Does it spray the prey then track it down as it gets goofy? That is a done thing with venoms. Or it just spraying the area willy nilly, not knowing if there is prey around? That would use up a lot of spray.

I like your idea for a thing smaller than what you depict. Your system would work perfectly for a parasite / predator like vampire bat. Or a big bedbug. It would find prey then surreptitiously spray it from a safe distance - maybe from up in a tree, or the ceiling. Senses numbed, the prey does not then notice the creature (possibly with its extended family) slowly crawling in to quietly feed.

  • $\begingroup$ I envision the creature to have relatively poor eyesight but an excellent sense of smell and hearing. So I suppose the creature could smell or hear if a prey was in range, and then spread the toxin. $\endgroup$ Jul 20, 2017 at 0:11

Chiggers kind of do this - they release an anaesthetic before they release the acid that melts your skin, so as to avoid detection - various other biting things may do too, I don't know.

Overall I like your design and think that especially with the concessions you're willing to make on absolute realism due to the existence of magic, you're fine with this. One thing that occurred to me was that the creature's photosensitive skin could have evolved to produce the toxin from pores when light hits it above a certain (low) intensity. I don't know the equations you'd need in a realistic world, or whether they could be photosynthetically catalysed, but it seems borderline plausible to me - and magic would definitely do it obvs. That way you've perhaps solved the problem of how it diffuses enough of the stuff to have lots of it constantly around (in sun/moonlight).

You could keep the tail gland thing perhaps for spraying more concentrated doses in a defensive situation, which despite its general terrifyingness I can imagine it could need being so slow moving.

It seems like it could be an adaptation shared by a family of creatures, too.

All very cool.


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