Warning creative brainstorming to follow:OK, I can follow that. I'm an old StarCraft junkie as well, so very familiar with the idea of Zerg. Your Zergbies also sound to have a bit of Resident Evil in them, but maybe that's just me.
I have in my mind a micro-organism that was programmed for what we thought would be good purposes, but like so many evolutionary steps, this one made a huge jump. Most micro-organisms (for all their complexity) are relatively simple and just flow where the environment or blood flow takes them. In this case, you have cells that not only have their own means of moving through the host, but can communicate with each other through a link that can best be described as telepathic (though exact definition will take a long discourse to explain once it is studied in great depth years later). This explains the "hive mind" as well as the link to the Queen. Obviously there is something unique about her infection that makes her the center, but that would be the simple version.
Genetically, the cells absorb and can selectively rejuvenate viable DNA at will. It is not perfect, but it uses an extremely rapid form of trial and error, like a geek with their first Rubik's Cube and they quickly decode and figure out what they want to use and what they don't. A sort of tiny organic Borg, if you will. It can then hijack almost any cell that is still salvage-worthy and can use it and cause rapid replication on a phenomenal level, so fast it can be seen growing with the naked eye. At this point I think of "The Thing" where what would appear to be blood could even move across the floor on its own before dying from lack of energy after a while.
The flesh would appear often misshapen and cancerous, at first glance. This is where extra limbs and deformities can easily come in, as well as strange combinations that mostly work by choice, but not always. It could grow wings, but then they might be too small, so it takes a minute or two before it then decides to grow them bigger and test them until they are of functional size, then it moves on, etc. Through such perverted mutations, you can create living ships (with a mechanical core of some kind), though the big thing will be for it to have energy.
This kind of cell growth and advancement must come at a cost and that is that those cells are going to need to feed and absorb nutrients of some kind as well. To this end, victims may often be consumed as food. They would only leave victims intact if they wanted to increase their numbers. Being without morals though, they have no problem being cannibalistic either. They might eat half a person and leave the rest to become one of their own, only to consume that minion later to sustain those that are needed. They can even selectively consume portions of themselves to fill this requirement, leading to loss of skin and flesh in areas they care little about. They have no interest in appearance, only functionality. As time would go on, they may appear to shrink and go from muscular brutes to near skeletal remains. The byproduct of this consumption would also appear as a residue or slime that is all that is left of the consumed cellular material. Thus leaving a trail of gore in their wake would tend to be a bit of a calling card that they had been there. Eventually this would lead to a form of starvation or what would appear to be total decay, but what could seem a dead corpse could still easily hold a small core of infected tissue that is alive and staying almost dormant until a new host happens by. Such a sleeping monster could remain viable for a very long time, and if frozen in space could easily reanimate once thawed out.
The down side of such creatures is that the only real way to kill them is complete destruction of the tissues and microbes. Fire or use of a phaser (and so on) that completely destroys the cell structure. Killing the brain would slow them down as controlling the body becomes much harder when depending on the hive link. This leads to the sluggish crawlers. The hyper Zergbies need a functioning nervous system to exploit. They prefer to use one that is intact, but will grow one if needed.
In this version though, there is no coming back. Once it has you, you're done. If infected, your only chance would be if say it were a wound on the arm or leg and you quickly removed the limb. In theory, a person might be able to be saved using a transporter as well, filtering out the foreign organisms, or restoring a person to a saved state, though how viable the memories and such might be based on how long the pattern was saved and so on becomes a matter of debate...another stream of technobabble for another day.
So, am I close on anything here? I'm throwing this at the wall and looking to see if any of it sticks. I may or may not have created a few evil things in my time, so this is just a simple mash-up off the sci-fi cuff. I just need some guidance so I know what to say I'm seeing and what I should not step in so that I avoid contradicting the real story and such. Thanks for the clarifications and I hope this might have been useful in some way.
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XO LtCmdr Samantha Waters
Lone Wolf
lonewolfdagaz@hotmail.com