Ooh yeah, but kinda long. And too derivative – we can’t simply do this the lazy way we normally do it on the CC.

(I’m very guilty of this, as you know.) It’s got to be freshly rewritten. I don’t think they’re going to print something if it’s obvious that all we did was rearrange or replace certain words.
How about this:
This squirming mass of fetid, mottled violet and brown flesh could be one enormous sluglike creature, or several smaller ones. Tentacles dripping foul mucous flick and lash back and forth from every conceivable opening the snaky forms allow.
Illithocytes are deformed, eyeless things that push their way through the moist darkness with their tentacles, leaving a wide track of foul mucous behind them. They spend most of their time in large family masses, entwining their bodies and moving as a group. They gain their sustenance solely from whatever psychic radiations they find.
Illithocytes were once illithid tadpoles that survived the fall of a mind flayer empire. With no warm bodies to inhabit, the tadpoles were forced to adapt or die. Those that survived learned how to grow new life on their own, and evolved into a new self-contained species. Illithocytes now bud new members of their species from their own bodies, rather than other creatures.
An individual illithocyte is 4 feet long, and weighs 20 pounds.
Combat
Illithocytes are aggressive, preferring to strike before their adversaries can react. Groups of illithocytes direct their attacks against a single target, maximizing the benefits of their ability to fight in close quarters. Being the chief source of nutrition for the ravening neothelids (see the Expanded Psionics Handbook), illithocytes use their aggression to drive these predators off.