I envisioned their movement through solid materials as more supernatural than mechanical - they pass through the materials as if they were soft and pliable to them. As such, I didn't put much thought into their castings. The sub was inspired by a fishing trip with my son as I was baiting the hook.
As for immunity/resistance to poisons, I believed I covered that off with the passage:
"They are not indestructible, but are able to survive within the earth to the depths of several miles, subject to the immense pressures, temperatures and the toxicity of both air and stone"
So, metals, acids, CO, CO2, H2SO, etc, are all found in the depths, so all inorganic poisons and simple organic poisons would be protected
The title is a people's name for the things - they are effectively immortal. Another piece of somewhat dangerous, somewhat odd, magic to throw in one's world, not unlike the Voracious Slug.Go to Comment