Erchius Horror (codex)
We are calling it the Erchius Horror in spite of a true name for it. When the Facility was locked down, we were trapped down here with it. And believe me, 'Horror' is a perfect description for this creature.
We found it in a deep vein of Erchius crystal, and upon uncovering the thing it awoke. At first we thought it was a sentient Crystal, but a desperate attack with a mining laser cannon uncovered a single, unblinking eye within.
It fired streams of searing plasma at us, destroying most of our equipment. Attacking up close was impossible, those who got too close were drawn inside it, transformed into mutant servants for the monster. We fled, and the mutants followed.
The laser cannon was left intact, however. Perhaps a braver soul than I could go back and use it to destroy the creature. They would have to be agile enough to dodge its beams, and strong enough to defeat its corrupted lackeys.
A disturbing thought occurs - This thing COULD be a parasite, but who is to say creatures like this aren't instead the source of the crystals? We may never know for sure, but I hope for everyone's sake that this plague doesn't leave this doomed moon.