The Moon Jungle is known for its enormous trees with dense vegetation and fauna. However, there is a path where no tree or bush ever dares to block the way of day or moonlight. In this path stands Tonamecoatl, the sun snake. As thick as a jungle-redwood trunk, as long as the eye can see, his darksome scales are a sight to behold. He stood there since human history can remember, protected and respected by the forest itself. He is deemed sacred by the moon people and his existence is revered.

Is the Tonamecoatl biologically possible?

While wandering, i found this question about big snakes and it sparkled some interest in a different design. What I want here is the plausibility of the existence of such organism, living stationary and getting energy solely by the sunlight. There is some sort of magic in my world, but I am not interested in using it directly for this explanation. Points in my design:

  • His scales are his source of energy. They are biological, convert sunlight into energy and use it to mantain his biological processes.
  • He lives in a tropical rainforest. There is abundant sunlight year-long.
  • He survives night and storms. Situations where sunlight is absent or dim, or weathering must not pose a big threat.
  • His size is impressive. Whatever shape his cross-section is, he must be long. Bonus points if one end of the body could not be seen while standing next to the other.
  • He is stationary. He does not move.
  • He is unique, there is no other sun snake in the known world.
  • Fauna and flora does not damage his survival. He is not attacked for food, plants do not block sunlight, microorganisms do not parasitaze or decompose. I can accept this being of magical nature not intrinsic to the creature (Maybe someone cast a spell on it). But bonus points if this behavior can be explained, even if not entirely, by science.
  • His appearance resembles a snake. Head, eyes, mouth and teeth (Even if serving no purpose).
  • He is biologically immortal or at least really long lived.
  • The means of his origin may be overlooked in favor of the possibility of his existence.
  • $\begingroup$ for one thing a snake does not have enough surface area to supply its metabolic needs through photosynthesis. $\endgroup$
    – John
    Commented Jul 7, 2021 at 20:02
  • $\begingroup$ While we welcome speculative questions not necessarily intended for any particular world, you still need to realize that (a) no, the creature can't exist to the standards of the science-based tag. (b) Yes, the creature could exist in a fictional world where you set the rules, which are necessary to explain for the reality-check tag. The science-based, reality-check, and hard-science tags are not intended to be used in combination - they scope the answers in different ways and are mutually exclusive. (Note, a reality-check Q vs. real life is off-topic.) $\endgroup$
    – JBH
    Commented Jul 7, 2021 at 23:03

1 Answer 1


Apart from calling it a snake, your description seems more fit for a giant cactus: since it doesn't move and photosynthesize to get energy, basically it's a giant plant with scale like leaves.

Not moving it has also a lower metabolic need.

The only issue might come from the reduced exchange surface: cactii have leaves turned into thorns to reduce the water losses in a desert environment, which can be counterproductive in a tropical environment.

But I guess the magic which you use for explaining is lack of enemies can also explain this.


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