On the making of the Horta:
"It was a large, pancake-shaped glob of gook with a thickened, raised center and fringe around its circumference. It sure didn't look like much. As Janos took the glob out of sight to put it on, Gene Coon raised an objection. 'Bob, why are wasting time with this?' Suddenly, the blob skittered around the corner, making straight for us...."
https://memory-alpha.fandom.com/wiki/Horta#Background_information

The Horta were a sentient non-humanoid silicon cycle life form native to the planet Janus VI. Horta anatomy was composed of a material similar to fibrous asbestos. Horta physiology was very different from the carbon-based lifeforms more commonly found in the galaxy. Horta were difficult to detect with tricorders, and were invulnerable to type 1 phasers, though they could be injured with an adjusted type 2 phaser. They fed on rock, and thus they were nourished just by tunneling. Horta...
@MisophonicSpree
Do you think the creature in this episode is carrying any silicon based virus or bacteria that could infect the humans?
Spock proposed the theoretical existence of silicon based life, but in #ObserverEffect the NX-01crew seemed to indicate that they had been trained on the deadlines of a potential silicon based viral infection.
Schmitter, we barely knew ye!
I'm craving Starburst candies right now. Don't know why.