A New Kind of Zerg
Sertum III, a small, backwater world in one of the abandoned sectors of the Talon IV asteroid belt. A planet so worthless that even the Zerg ignored it. It was small, insignificant, and out of the way. It was the perfect place to be if you didn't want to draw attention to yourself, or if you were doing something that could get you killed if anyone found out.
Experimentation on Zerg wasn't a new thing. The confederation had been doing it since they were first introduced to the new species, bur they did make it law that noone is allowed to perform these experiments without proper authorization. For this reason, non-confederate and private investors who wanted to continue their research, had to hide their actions on dead worlds to avoid possible persecution. Sertum III was one of those worlds.
Though their experimentations did have to be performed in secret, people were still needed to provide both resources and personnel for the labs. The planet was originally populated with roughly fifty colonists. As the need for more manpower grew however, the population grew too. Fifty people is not enough to repopulate a planet, but it is enough to populate a butchery, and a butchery is exactly what that planet became.
The scientists working on Sertum III were trying to determine exactly how the connection could remain so strong between the Overmind and its minions. They compared the brain structure and function of most species of animals to that of several Zerg strains. They were able to determine that a mutation in the cerebellum, the lower back of the brain, was how the Overmind was able to apply it's will and control the behaviour of the Zerg race. They also discovered that many of the Zerg strains were actually different species of animals found through the galaxy who's DNA had been assimilated and genetically modified to serve the Zerg's twisted goals.
Those in charge of the medical experiments decided to try and sever the Overmind's control over their live test subjects. They were able to succeed in this task and revert the "animals" mentality back to before the Zerg's taint. They presumed that the creatures, without the will of the Swarm to guide them, would become peaceful creatures like their unmodified ancestors. This assumption proved fatal and cost them their lives. Yes, the former Zerg subjects they harbored no longer served the Swarm, but they were anything but peaceful. The medical technicians who worked the labs failed to realize the fact that though these creatures were no longer being fuelled by the will of the Overmind, they were still originally, savagely heinous races before their mutations.
The people of Sertum III were slaughtered. They played God and payed the ultimate price for it. Like any other animal, the newly "freed" critters, finding themselves in a strange new world in a strange new existence, lashed out and defended their beings. Violently. Those in the immediate presence of these beasts were to first to be cut down, teeth gnashing. The instinctive animalistic fury doomed the doctors before they could even register the situation in their heads. As the number of dead continued to rise, so did the Zerg's efficiency. After a few kills, they began to experiment themselves and conform to their new bodies. Now, along with the use of teeth, were the use of razor sharp scythes and poisonous spines. By the time the last member of on-duty staff present in the lab was exterminated, the Zerg forces were already at their peak performance.
They then proceeded to clear the inhabitants of the rest of the base. They killed without remorse; man, women, child, it made no difference.
As soon as they felt as though the threat were gone, they left to find a new home. All of the newly liberated, self-directing, self-governing, self-ruling, Zerg strains expressed both a common tendency towards social interaction, as well as individualism. They all worked and communicated together, but each one was an individual with individual characteristics. The different species, though were not hostile towards each other and did socialize with each other well, obviously did not pack together. Each race preferred to live and work with their own kind.
The Zergling's social structure closely resembled that of the now extinct wolf pack, but with some obvious differences. The packs were much larger and ranged from a dozen, up to about fifty or sixty Zerglings per pack. Though their communicative skills were restored to their former state, their intellectual capacity changed very little. This meant that though they could plan and coordinate their attacks on prey, the tactics were restricted to little more than the "surround, sneak in close, then run in for the kill as fast as possible." Though this method was crude and simple, it did prove quite efficient for the quick Zerglings.
The former Hydralisks proved to be a more reserved and reclusive. They stayed in groups of up to, at most, six. They were typically found in groups of three or four. They were also fiercely territorial. Though they did not attack other Zerg unprovoked, they did attack those who ventured too far into their marked territory. For their large size, they were surprisingly stealthy. When hunting they tended to use their scythes in opposed to firing their poison spines, which were used more as a last resort if the element of stealth could not be properly achieved.
The Mutalisks where an exception to the other Zerg strains. They did not instantly revert back to their previous instinctive habits like the others did. When they were freed, they stayed separated and secluded. They also did not attack those who previously imprisoned them. While the other races broke free from their tempered glass, gelatinous filled stasis cells, the Mutalisks remained confined and instead reverted to a state closely resembling hibernation. They only escaped the compound about a week later when the lab experienced a total system shutdown, releasing them from their stasis tanks. They also did not socialize or interact at all with the other fugitives. As soon as they escaped, they scoured the surrounding area and established their new home in the cliffs above an expansive lake, a few dozen miles north-east of the compound.
Their behavior in nature was completely baffling. They were completely nocturnal and were only active at night. During the day they would recede into caves they dug into the cliff face and slept. Their bodies still produced the dreaded glaive wurms, but served no purpose to the Mutalisks other than for defensive purposes. At night, they fished. Fish ,and whatever other aquatic animals they could catch, was what their main diet consisted of. For this reason, they stayed at the lake and were never found very far away from a large body of water.
Defilers were the scavengers of the Zerg. They did not hunt, and adversely could not hunt if they wanted to. They had no true means of attack and their host of skills where solely used as a last means of defense. They tended to hang around groups of Zerglings and Hydralisks, feeding off the scraps left behind. They were for the most part loners, usually only one was found accompanying any given group at any one time. On extremely rare occasions, they could be found in pairs, either scavenging or picking off the weak and dying, eating the animal alive.
Finally, a single Ultralisk could be seen wandering throughout the entire planet. Due to it's massive size, the lab only harbored one of them. Surprisingly though, the Ultralisk left to it's own devices, turned out to be completely vegetarian instead of carnivorous like it's former brethren, despite it's ferocity. All other animals of the planet quickly learned to respect the titan. Even though it was the most dangerous and obviously unrivaled, it did not attack unprovoked. This mutual understanding meant that the ultralisk was free to come and go throughout the entire planet as it please. In some cases, it was even a welcoming sight. The presence of the Ultralisk meant safety for many smaller animals, who tended to stay close for protection.
The rest of the Zerg strains, unfortunately, were not as versatile as their companions and died off soon after their release. The three Queens within the compound could not survive without the will of the Overmind. Out of the three Queens that went through the lobotomy, only one survived the separation between itself and it's supportive consciousness light-years away. The lone queen suffered from insanity soon after. Within 24 hours of it's escape from the lab, it committed suicide by chocking itself on it's own sticky, green, "Ensnare" fluid. The body was also infected with several of it's own parasites and an attempted broodling spawning, which consumed a large, gaping hole in it's side, still bleeding and raw leading into it's body cavity. Within the cavity were two, grotesquely distorted, partially formed broodling fetuses.
The Zerg Larva, being the closest to a true Zerg strain, were not being experimented on. Also, it's ability to mutate into other Zerg strains, scared the researchers. For these reasons, Larva were neither held in the compound, nor the planet. Drones were also restricted from the planet for the same reasons. If a single drone were able to mutate, the entire population of the planet could be in jeopardy. Scourges, though they did escape unharmed, died off within a few days from starvation. With no way to hunt without destroying themselves in the process, they quickly succumbed to lack of nourishment. Finally, because of the overlord's sheer size, in addition to it's direct influence over the other Zerg in the area, Overlords were not allowed to be brought to the planet.
Within two and a half months, all species of animal on the planet had establishes an equilibrium with each other. Each having their own respective territories, each having a natural balance with the world around them. On any other planet, if Zerg were present as well, the planet would be assimilated. Here though, life went on, Zerg lived together instead of competed for supremacy. Here, everything lived in harmony...
Including the last three surviving humans on the planet.