Definitely looks grown. And it’s probably quite large, if we assume that connecting stem-like thing is large enough to allow a humanoid-sized being to traverse it without crawling.
I am considering tackling this weird thing, but like the pod ship from "Beyond The Farthest Star" I will tidy it up some to make it look a bit more credible as something that could be constructed as a miniature.
I can perhaps see it as something like the power leach Orchid from PICARD and/or a phylosian design—which would explain how Enterprise and the D-7 were not able to fire effectively...unless that was also a property of the Delta Triangle as well. Perhaps a joint design done in concert with the pod ship aliens. Here, I would say the stalk is a collector of some kind. Sadly, the pod aliens drew the wrong energies to themselves.
It very much reminds me of a deep sea angler fish. That "flying saucer" that's attached to it could be a lure? "Ooh, look, Zarkon 7!" "What is it, Husband-UNIT?" "A flying saucer near that enormous tree that can't possibly be hiding anything behind it! Let's go investigate." "Very well." * CRUNCH SMACK SLURP *
Maybe the larger part is actually a giant space leach organism and it's extended a feeding tube to a smaller mechanical craft?
Playing catchup on this thread, I REALLY like how this came out. Like you said, the vertical orientation is different from the norm. Kudos, @Warped9 .
Is that a gray model with green environment lighting or something else you're doing with the reflection maps?
Huh... curious, then why it's gray underneath without any hint of color. Must be an artifact of the rendering process.
Not really surprising, but the onscreen version lacks a lot of detail. Its shape is its most interesting feature.
I know you're not being literal to the drawings, so these are just a few observations about how your model differs. The nose hull of the original sketch appears to curve down a lot more and the neck appears longer and doesn't feature as strong an S curve along the bottom where it meets the hull. Also, the wings on the sketch wrap around the center shape more. The result, possibly intentional, is the 3D version looks less organic and planet like. The front "egg" might be a big kidney shaped as seen from above. And, frankly, this is one of those designs which probably only has a few good angles, as it's just weird. I bet it's the Phylosian ship.