A hive mind whose component parts are microscopic - sentient viruses anyone?
You mean like the Enigman Invaders? What has been frustrating the players in my current SM campaign is the fact that the Enigman Invaders are not any one single species. Instead, they are a conglomeration of many, many different species which have been assimilated into the Overmind.
And guess how the assimilation process is done? Through the spread of a virus that overwhelms the brain and nervous systems of the creature, allowing it to be controlled by the Overmind.
Fortunately, I have some great players which do not force me to come up with tens of thousands, even millions, of different species the Enigmans have assimilated. They actually help out some with their own imaginations. In one session, one player investigating a dead Enigman ship said, "Well, I see the Captain was a Species 8472 while the Helmsman was a Species 14832." Of course I howled with laughter. I couldn't help it. At the time, it was so funny.
Ever since, we all now use the same terminology, Species 231, Species 583922, Species 54, etc.
You know, it makes me wonder how many different life forms we have come up with in all the movies, novels, and TV shows... Couple million? Half billion?
rmfr