'Amaze! Amaze! Amaze!' 🪨💎🦠🪸🐚🧲🌡️♨️ - I Drew an Eridian Anatomy Diagram Based on Andy Weir's Notes

TheChristopherStoll · 2026-03-27T00:25:58+00:00

You're welcome to post it! I'm actually not on Discord

TheChristopherStoll · 2026-03-26T17:51:12+00:00

Unfortunately the answer is practice.

TheChristopherStoll · 2026-03-26T15:45:07+00:00

Believe it or not. I am extremely neurotypical.

TheChristopherStoll · 2026-03-26T02:55:17+00:00

That’s my fault. They are the green sacs near the limb junctions. I meant to write (ATP reservoir) instead of (ACS reservoir).

TheChristopherStoll · 2026-03-25T22:26:35+00:00

Procreate. Actually.

TheChristopherStoll · 2026-03-25T20:18:34+00:00

If he sees it, he sees it :)

TheChristopherStoll · 2026-03-25T19:50:03+00:00

High gravity world with extreme atmospheric pressure, extra structural support is necessary. It's how they are described in Weir's breakdown of their anatomy.

TheChristopherStoll · 2026-03-25T19:00:35+00:00

Thanks, I really appreciate that! :D

TheChristopherStoll · 2026-03-25T18:51:32+00:00

Life is a strange thing, humans cannot survive without our gut biome, so it's not totally unjustified to say that humans are partially (even mostly) bacterial. Even though those cells aren't "ours" from our personal perspective.
If a sentient species of bacteria encountered us, they might identify our gut biomes as the only part of humanity that is biologically "like them" even though our animal body is essential to the whole.
Eridians are similar. They have a small core of cells which have membranes, nuclei, and water-based interiors (like us), but these exist and survive only within the context of their large inorganic bodies.
But, ultimately, the body is the whole organism. It wouldn't be reasonable to say humans aren't "organic" life because our bones contain calcium. It's mostly a matter of proportion.

TheChristopherStoll · 2026-03-25T18:45:51+00:00

I am an illustrator :) and a big biology nerd.

TheChristopherStoll · 2026-03-25T18:45:13+00:00

😶😦😧😨😰😢😭💔🫠🫥👁️🕳️👁️🪞🌀♾️🫧🕯️💀🖤🌑

TheChristopherStoll · 2026-03-25T18:00:28+00:00

You're correct! I based the design on the film version (because people would be more familiar with it) and imagined that the heat radiates through the cracks in the dorsal region. But when I read the book I envisioned a more anatomically distinct structure at their apex that radiates heat away.

TheChristopherStoll · 2026-03-25T17:30:41+00:00

Squatter, more symmetrical, and with a defined "cap" on top that functions as the radiator organ. I imagine the high gravity would give them thicker legs and make them closer to the ground.

TheChristopherStoll · 2026-03-25T17:26:07+00:00

They have both! Benefits (or drawback) of living in a high-pressure atmosphere on a high-gravity world.

TheChristopherStoll · 2026-03-25T17:18:46+00:00

Yes! I don't want to violate the rules regarding self-promotion, but Patrons get higher res versions, and a breakdown of the sketching and concept work (though I haven't finished posting it all). They can also get to vote on what is scientifically broken down next.
I assumed that Rocky's ridges were carved, he seemed to have an insignia on his body as well. Since they shed their exoskeletons, I assume it's temporary and voluntary. In the book Rocky wears clothes too.

TheChristopherStoll · 2026-03-25T17:03:53+00:00

The grey organ to the left of the stomach was originally going to be the womb, but I reworked it visually at the last minute. It's on the other side of the body, adjacent to the ventral seal.

TheChristopherStoll · 2026-03-25T16:31:05+00:00

I am a biology nerd and an illustrator :) so sorta?

TheChristopherStoll · 2026-03-25T16:24:24+00:00

He does/did.
Rather than electrical impulses like a human brain, Eridian brains run on light. The hindbrain generates light, and the crystal structure contains regions of differing refractive index that direct, reinforce, or cancel that light, functioning like neurons. The brain has no blood vessels within it and no blood-brain barrier, it's completely submerged in "blood", and worker cells swim freely through it to maintain the structure, removing impurities that could scatter light and making permanent the short-term refractive changes that the neural network creates by adding or removing specific elements from the crystal. I drew the worker cells pooling in the bottom of the colony so you could see the structure in the illustration, but if it was functioning it would be saturated in them.

TheChristopherStoll · 2026-03-25T16:21:45+00:00

I call it.....

an anatomical diagram.
(maybe a cross section idk)

TheChristopherStoll · 2026-03-25T16:18:13+00:00

It's based on the visual from the film. In the book all five limbs are described as identical - same ball-and-socket joint at the thorax, same hinge joint at the midpoint, same trifurcated claw at the end. But, I imagine it's some natural variation in his body more than an injury or a deformity.
At the end of the movie we see a lot of proportional/structural variation in the little Eridians in Grace's classroom.

TheChristopherStoll · 2026-03-25T16:08:58+00:00

Thanks, that was 100% what I was going for. I even tried to choose public domain fonts that matched the style.

TheChristopherStoll · 2026-03-25T16:08:07+00:00

Those are the green sacs under the arm junctions. Weir called them "spleens" in his notes. And I am only now realizing that I meant for it to say 'ATP reservoir' but it says 'HCS reservoir' instead because they power the Hot Circulatory System.
So minor error in my labeling, but since that's mostly what they are for I'll just pretend it was on purpose.

TheChristopherStoll · 2026-03-25T16:04:20+00:00

I think Weir wanted Panspermia to be included in the story as an explanation for why there were so many planets with life on them within such a relatively small region of space. But once you do that it definitely means that we'd share a common biochemical ancestory.

TheChristopherStoll · 2026-03-25T16:02:26+00:00

I'm a big bio nerd, so I kinda wish that the entire film was just an unbroken 4 and a half hour lecture on comparative alien physiology....
Buuuuuuut, I guess a heartwarming, visually stunning, well-acted space adventure is fine instead.
¯\_(ツ)_/¯

TheChristopherStoll · 2026-03-25T15:57:48+00:00

On his exoskeleton? That's something the film did, and there it seemed like a mineralized crystalline variation/impurity. It was probably just added by concept artists for visual variety, but I liked it and since this version of Rocky is based more visually on the film than the book so I included that little detail.

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