Spoiler Man!
It has the exact same stats as a shoggoth except it is 50% faster, super-aggressive, but has no damaging attacks.
It has various vocalisations including: The specifics of fungal infection, which attributes are associated with various mutation paths, where the nearest unexplored remote building is(and adds a map marker), “Spoiler Man, Spoiler Man, does whatever a spoiler can” and the rest of the Spoiler Man theme, what triggers trifid growths, how much damage and accuracy is required to kill a shoggoth, where the nearest player-created vehicle is(often lying, and with a rigged R.N.G. that will generate a similar lie over and over again for days), where a specific skill book that would currently train the player can be found, the skill caps for various things, lab finales(including map notes), how to craft diamond gear, a code that will get the player through the nearest lock, how to turn on debug mode…
If you reduce it to 10% health, then it turns into a shoggoth.