Table of 



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After the Xel’Naga failed in their experiments to make the Protoss into the pinnacle of genetic evolution, they abandon their first born and travelled the galaxy for thousands of light-years.  Finally, they discovered the planet of Zerus and took an interest in a small, semi-parasitic lifeform they called the Zerg.  Though little more than a worm, the Zerg managed to survive in the hostile atmosphere by burrowing into host creatures and using them to feed, mate and alter their local conditions.

Each time the Zerg assimilated a new species, it added that species genetic substrate to the Zerg’s own, growing code.  Overtime, the Zerg began to choose only the most advanced genes, discarding the others.  Eventually, the Zerg managed to assimilate and infect every species on its own planet that it deemed worthy and to eradicate all other life lest it pollute the Zerg genome.

The Xel’Naga witnessed how the Zerg managed to drive the evolutionary development of the species it infected.  Within a few generations, highly disparate species came to resemble one another: all developed variations of the Zerg common features: carapace, spines, claws and fangs.

Hoping to control the Zerg development, and avoid the factionalism that led the Protoss to apparent ruin, the Xel’Naga created a single sentience that would serve as the Zerg’s collective consciousness.  This entity, the Overmind, was capable of instantaneously communicating with and controlling any of the Zerg breeds anywhere on the planet.  Soon, the Overmind became self-aware and conscious of its Xel’Naga masters.

The Overmind quickly developed a hierarchy to manage the growing swarm of beasts over which it ruled.  It began to develop new, completely unique Zerg breeds, and produced the Cerebrates--semi-autonomous “lobes” that carries out specified functions for the species.  While these Cerebrates had unique personalities and functions, they remained unquestioningly enslaved to the Overmind’s will.  The Overmind developed an entire hive structure, complete with Queens, Overlords, warriors and drones.  It linked all its kindred through a tele-empathic link and fed them all on a genetically engineered bio-matter known as the Creep.

The Overmind was single-mindedly concerned with pushing the Zerg swarm to further evolve into the apex of natural perfection.  To do so, it realized it would have to leave Zerus and journey the stars.  Working in secret from its Xel’Naga observers, the Overmind managed to attract a space-faring race of behemoths to the planet’s surface.  It quickly assimilated the species and with it, the ability to travel the stars.

The Overmind soon launched its children into the stars, directly at its Xel’Naga masters.  The Zerg swarm overran the Xel-Naga world ships, destroying them and assimilating the parent race.  Soon, nothing was left of the ancient race except space debris and a few units of its genetic code, stored in the growing Zerg genome.

When it assimilated the Xel’Naga, the Overmind learned much of the galaxy and of the Xel’Naga’s first child-race, the Protoss.  Overcome with a desire to reunite with, and assimlate, the Protoss, the Overmind launched the Zerg into space.  For decades, it travelled from system to system, assimilating worthy species and devouring all others.

The Overmind came to realize that its substantial genetic bank had no provision for countering the Protoss’ psionic prowress.  So, it sought to assimilate another psionically talented species.  Finally, it found a rather unpromising, young species that, by chance, happened to have some small psionic potential that might be captured and improved upon by the Zerg mastery.  And so, the Overmind set it sights, and loosed its children, upon the planets of men.

Though a unified whole, the Zerg may be subdivided into different groups, referred to as Broods, that act under the authority of the various Cerebrates.  Each Brood has particular functions and characteristics best suited to execute its duties.  Though little is known of the Broods and their Cerebrates, Terran explorers have managed to learn a little.  They have named each Brood after mythological beasts from Earth’s history.

The Command Wing
Cerebrate:  Daggoth
Estimated Size: 6.5 million
Primary Directive:  Command Fleet
Brood Color: Red
     Tiamat is actually a massive living fleet of Zerg carrier-breeds, warriors, and functionaries.  Rumor has it that the Overmind travels in the heart of the fleet’s biomass.  Daggoth is a master of space tactics and only rarely deploys his swarm to a planet’s surface.
     As the overlord for the largest Brood, Daggoth’s authority is practically limitless, save for that of the Overmind.  He is strong-willed and autonomous, often forming his own opinions as to what is best for the Zerg, and willing to prod other Cerebrates into joining with his opinion.

Cerebrate:  Nargil
Est. Size:  5500
Primary Directive: Hunter Swarm
Brood Color: Green
     Despite its small size, the Fenris Brood serves a vital function for the Zerg.  It is charged with scouting for new species to assimilate.  Its honed tracking skills are also used to track down (and exterminate) abberant Zerg dissedents and other escaped enemies of the Swarm.  Quick, clever, and brutal, the hounds of Fenris have chased many a foe until it simply died of exhaustion and fear.

Cerebrate: Gorn
Est. Size:  6000
Primary Directive: Terror Squad
Brood Color: White
     The Baelrog Brood manages to make even other Zerg uncomfortable.  Known for not only their savage battle tactics, but their voracious cannibalism, the Baelrog are bred and trained to attack without hesitation, mercy or self-consideration.  Foes have been known to flee at the first sign of the pale white carapaces of the Baelrog Zergling charge.

Primary Strikeforce
Cerebrate: Zasz
Est. Size: 10,000
Primary Directive: Primary Assault Force
Brood Color: Orange
     Led by Zasz, the Zerg’s greatest terrestrial tactician, the Garm are often the first to engage an enemy species.  Favoring hit-and-run raids, stealth operations, and acts of sabotage, Zasz delights in befuddling his enemies even as he brings down the killing stroke.
     Zasz’s cleverness exceeds his battlefield role, however.  He is inexplicably driven to learn all he can of his sibling-Cerebrates, claiming it is to advance the Swarm’s efficiency.  But Zasz often comes across as obsequious, and some of the Cerebrates distrust him.

Cerebrate: Araq
Est. Size: 3 million
Primary Directive: Primary Support Force
Brood Color: Purple
     The Jormungand overwhelm opponants with its seemingly endless supply of warriors.  Producing new Zerglings even in the midst of a pitched battle, Araq’s forces leave few survivors.  It is from the Jormungand that the other Broods recruit most of their elite warriors.

Cerebrate: Kagg
Est. Size: 2.6 million
Primary Directive: Heavy Support Force
Brood Color: Blue
     Where the Jormungand kill all enemies before them, the Surtur eradicate all forms of life.  Once-green fields are transformed into smoking, ashen wastelands.  The Surtur strains have been bred for a ferocity matched only by the Baelrog and share that Brood’s cannibalistic tendancies.  Kagg’s forces dwell deep within the Tiamat Fleet, likely near the Cerebrate, and released only in the most crucial situations.

Below is a list of the main Zerg breeds encountered by enemies and victims of the Swarm.  There are doubtless other breeds, both mutated species assimilated into the Zerg genome and original Zerg strains. 

Genus:  Original Zerg Strain
STR= 1D: 
DEX= 1D: 
CON= 4D:  Resistance 5D.
KNO= 1D:
INS= 2D: 
HP= 32 (Eggs have HP = 40).
Scale:  Character
Length:  2 m
Height:  1m
Damage:  None.  Larva have no attacks and will only attempt to flee combat.
Armor:  6 (Eggs have an armor of 20).  Can be increased by 4 per Ground Carapace Evolution.
Movement: 5 m 
    Larva are spawned by Zerg Hives and carry within them the entire Zerg genetic code.  At a command of the Overmind, they may pupate into an egg stage, and then transform themselves into any Zerg breed as along as the local conditions are right (there are adequate resources to nourish the pupating larva, etc.).  By themselves, Larva show little intelligence and no free will.  They rarely travel more than a few meters from the edge of the hatchery that spawned them.

Genus:  Gashyrr Wasp
STR= 5D:   Digging (Burrowing): 8D
DEX= 1D+1:  Brawling (Attack with front spines) 2D+2;  Running 4D.
CON= 5D:  Endurance 6D.
KNO= 1D: 
INS= 1D+2:  Search: Natural Resources: 6D. 
HP= 25
Scale:  Character.
Length:  3 m.
Height:  1.8 m.

  • Spines: Drones may  spines a short distance at attackers.
    • Damage: 5D.  May be augmented 1D per Missile Attacks Evolution.
    • Range: 2 / 5 / 10 / 15
  • Chewing:  Drones may chew at armor and reduce its strength even if they cannot pierce it.  For each round the Drone chews on a piece of armor, reduce its Armor Value by one.
Armor:  10.  May be augmented by 5 per Ground Carapace Evolution.
Movement: 15 m / round.
     Drones are the worker-breed of the Zerg.  Primarily, Drones mine and transport resources and nourishment to the Hatcheries, from which they are funneled through the Creep to feed other Zerg.  Like Larva, Drones carry an expansive, yet usually unexpressed genetic code.  At the command of the Overmind or one of its Overlords, the Drone can lodge itself in the Creep and create a new Zerg structure.  They are entirely necessary for the establishment of new colonies.  Drones show some signs of independent intelligence, necessary to problem solve when extracting resources or choosing the best place to pupate into a new structure.
     Drones are excellent diggers and can burrow themselves deeply into the ground within 1 round (more for harder soils).  They often burrow to avoid detection or attacks.

Genus:  Gargantis Proximae
STR= 10D: Lifting 14D.
DEX= 1D+1:  Flying 3D.
CON= 10D: 
KNO= 2D+2: Tactics 4D.
INS= 4D:  Search 5D.
PRE= 1D:  Command 4D
HP= 90
Scale:  Starfighter
Length:  30 m
Height:  10 m
Damage: None.
Armor:  30.  May be increased by 5 for each Flyer Carapace Evolution.
Movement: 15 m / round (flying) in atmosphere.  Space = 4.  Incapable of hyperspace travel.  Some may be Evolved for greater speeds (+10 m Atmosphere, + 2 Space for each Pneumatized Carapce Evolution).
Cargo:  None.  Through the Ventral Sacs Evolution, the Overlord can be altered to carry up to 2 units (40 Zerglings, 20 Hydralisks, 10 Ultralisks) in special growths under its belly.  (This is roughly equal to 100 metric tons of space).
Communication: Limited Telepathy:  Range = @ 1000 km.
     Overlords serve as local proxies for the Overmind and the Cerebrates, giving commands to larva and overseeing the functions of a Creep colony.  They also serve as field commanders for Zerg units in battles, hovering behind the front lines and directing the Zerg onslaught.  Some more evolved Overlords are actually capable of picking up Zerg field units and carrying them into battle, much as the Terran Dropship does.  Overlords are equally comfortable within atmospheres or in space.
     Finally all Overlords have such finely tuned innate senses, they cannot be fooled by cloaking vessels.  When one is detected, the Overlord will telepathically communicate its location to all nearby Zerg units.

Genus:  ZZ'gashi Dune-runners.
STR= 4D: Jumping 7D; Digging 7D.
DEX= 5D:  Brawling: 6D; Running 7D; Dodge 6D. 
     Zergling Dexterity may be increased 1D per Metabolic Boost Evolution.
CON= 5D:  Endurance 7D; Resistance 6D. 
KNO= 1D+1: Tactics: Small unit (Zergling swarm): 4D.
INS= 4D:  Search 5D; Stealth 5D.
PRE= 1D: 
HP= 25
Scale:  Character
Length:  2.4 m
Height:  1.8 m
Damage:  Because of their high Dexterity, many Zerglings will attack 2 times or more in a combat round.

  • Fangs: 5D.  May be augmented by 1D per Melee Attack Evolution.
  • Sickle-claws: 7D.  May be augmented by 1D per Melee Attack Evolution.
    • Quick Damage: 4D+9
Armor:  10.  May be increased by 5 for each Ground Carapace Evolution.
Movement: 20 m.  Movement may be increased by 5m/round with Metabolic Boost Evolutions.
     The Zerglings make up the primary ground-based military and scouting force for the Hives.  They have an extremely simple genetic code and are little more than wild beasts with a few genetic enhancements.  Some Zerglings show unusual intelligence and independence, however these individuals are usually quickly detected by the Overlords, reported to the Overmind and then thoroughly dissected in an attempt to capture their genetic superiority.
     Zerglings prefer to move in packs, much like Terran wolves.  They show a wide range of social behavior, including dominance displays, play and territoriality.  They rarely attack alone and the sighting of one Zergling is a good indication that a much stronger force awaits just around the corner.  Finally, some more evolved Zerglings are excellent diggers and may burrow themselves into the ground within one round to avoid detection or attacks.

Genus:  Slothien.
STR= 6D:  Digging 7D.
DEX= 3D:  Throw (Project Spines): 5D; Brawling: 4D; Running 5D; Dodge 4D.
CON= 6D:  Endurance 7D
KNO= 3D:  Tactics 4D.
INS= 3D:  Search 4D; Stealth 4D.
PRE= 1D: 
HP=  50
Scale:  Passenger Vehicle (2D over Character).
Length:  5 m
Height:  3 m

  • Sickle-claws: 5D.
  • Projectile Spines: 
    • Damage:  7D.  May be augmented 1D per Missile Attacks Evolution.
    • Quick Damage: 4D+9
    • Range: 1-5 (Point Blank) / 15 (Short) / 30 (Med) / 60 (Long).  Range may be extended by an additional 10 meters per Grooved Spine Evolution.
Armor:  23.  May be increased by 7 for each Ground Carapace Evolution.
Movement: 15 m.  Movement may be increased by 5m/round with Muscular Augments Evolutions.
     Once a peaceful herbivore on the planet Slothien, the Hydralisk has been manipulated by the Zerg to become one of its more fearsome warriors.  Highly intelligent and terrible to behold, the Hydralisk razes creatures and structures alike with its armor-piercing spines and claws. 
     Many more evolved Hydralisks have learned how to quickly burrow themselves into the ground (within 1 round) to avoid detection and attacks from enemies.  When submerged, the Hydralisk may make Instincts rolls to detect nearby enemies, choosing just the right moment to spring from the ground and ambush them.

Genus:  Brontolith
STR= 8D: 
DEX= 3D:  Brawling: 6D; Running 4D
CON= 8D:  Endurance 9D; Resistance 9D. 
KNO= 1D+1: 
INS= 4D:  Search 5D; Stealth 5D.
PRE= 1D: 
HP= 300
Scale:  Heavy Vehicle.
Length:  3.5 m
Height:  5.2 m

  • Bone Scythes: 
    • Damage: 12D.  May be increased 1D for each Melee Attacks Evolution.
    • Quick Damage: 4D+24
Armor:  30.  Armor may be improved by 5 points for each Ground Carapace Evolution the Ultralisk undertakes.
Movement: 7 m. 
     Ultralisks were derived from a massive, but peaceful, animal eons ago.  Now, these lumbering beasts serve as the heavy-armor corps for the Swarm.  With their thick armor and humongous scythes, they withstand huge amounts of punishment and lay waste to their enemies.  They are still fairly stupid and must usually be controlled by an Overlord.

Genus:  Mantis Screamer
STR= 5D: 
DEX= 5D:  Flying 7D; Throw (Propel Symbiote): 5D; Brawling: 6D; Dodge 5D+1
CON= 8D:  Endurance 7D; Resistance 6D. 
KNO=  2D: Tactics: Small unit (Mutalisk squad): 4D.
INS= 4D:  Search 5D; Stealth 5D.
PRE= 1D: 
HP= 90
Scale:  Starfighter.
Length:  10 m (nose to tail).
Height:  2-3 m thick.

  • Glave Wurm: Mutalisks may propel a symbiotic worm that lives within it at enemy forces.  The worm is incredibly hard and covered with armor-piercing edges. 
    • Damage:  9D.  May be increased 1D for each Flyer Attacks Evolution.
    • Quick Damage:  4D+15 
    • Range:  Atmosphere:  5 (Point Blank) / 25 (Short) / 50 (Medium) / 100 (long).  Space: 2 / 4 / 6
    • Fire Control: 0D (Use Throwing skill above).  Wurms may be launched at ground and aerial units alike.
Armor:  20.  Armor may be improved by 5 points for each Evolution the Mutalisk undertakes.
Movement: Atmosphere: 40;  Space: 6. 
     Mutalisks are the huge, winged nightmares that make up the Zerg's primary air force.  These screaming, clawed terrors may project a symbiotic lifeform they culture within their gut.  This worm shoots forward towards the enemy, exploding on impact and sending the symbiote's armor-piercing spines in all directions.
     Mutalisks work well in small groups, much as a Terran squad of fighter pilots would.  Mutalisks also function as well in space as in an atmosphere and have no apparent need to breathe or feed upon the Creep. 
     Some Mutalisks are chosen by the Overmind to undergo a transformation into a massive Guardian (see below).

Genus:  Evolved Mutalisk
STR= 8D: 
DEX= 2D:  Missile Weapons: Spitting (5D)
CON= 8D:  Endurance 7D; Resistance 6D. 
KNO= 1D+1: Tactics: Small unit (Zergling swarm): 4D.
INS= 2D:  Search 3D.
PRE= 1D: 
HP= 110
Scale:  Starfighter.
Length:  8.5 m
Height:  5.5 m

  • Acidic Spittle:  Guardians can hurl large gobs of acidic mucuous down upon enemy units.
    • Damage:  9D first round.  Reduce damage 1D each following round.  Regardless of whether the acid pierces armor, it will reduce its Armor Value by 3 for each round of exposure.  Damage may be increased by 1D for each Flyer Attacks Evolution the Guardian undergoes.
    • Quick Damage: 4D+15 first round.  Reduce by 3 for each round thereafter.
    • Splashing Effect:  The gobs spray out upon impact, doing -1D damage for each 3 meters from the impact site
    • Range:  1-10 (Point Blank) / 40 (Short) / 80 (Medium) / 160 (Long).
    • Fire Control:  0D (Use Spitting skill above).  The gobs of spittle are not very aerodynamic and are useless against other airborne units.
Armor:  30.  Armor may be improved by 5 points for each Flyer Carapace Evolution the Guardian undertakes.
Movement: Atmosphere: 35.  Space: 4. 
     Guardians are an evolved form of the Mutalisk, developed by the Zerg to counter ground troops from the air.  It's heavy armor lets it withstand more damage than its predecessor, but it is slowere and less versatile.  Guardians appear to be less intelligent than Mutalisks as well, but this may be due to their larger, slower bulk.

Genus:  Unknown.
STR= 2D+2: 
DEX= 6D:  Dodge 8D; Flying 7D
CON= 2D:  . 
KNO= 1D: 
INS= 3D:  Search 5D; Stealth 4D.
PRE= 1D: 
HP= 30
Scale:  Character
Length:  1.5 m
Height:  1 m

  • Biogenic Bomb:  catalytic chemicals within the Scourge cause it to explode forcefully when it impacts with an enemy unit.
    • Damage:  14D
    • Quick Damage:  4D+30.
    • Explosive Range:  Reduce damage by 2D for every 5 meters from the site of impact.
Armor:  8. May be increased by 4 per Flyer Carapace Evolution.
Movement: Atmosphere 45 m.  Space = 6
    Scourge are relatively small, bat-like creatures that hone in on enemy starships and collide with their hull.  Upon impact, the Scourge explodes, destroying itself and dealing harsh damage to the enemy.  For some reason, the Scourge will only lock in on flying targets, though the Overmind is experimenting with genetic combinations to render the Scourage more versatile against ground forces.
     As you might expect from a mindless kamikaze beastie, Scourges are neither very intelligent nor independent.  They obey the will of their Overlord without question or hesitation, sending themselves headlong into battle.

Genus:  Arachnis Brood-Keeper.
STR= 7D: 
DEX= 3D: 
CON= 9D:  . 
KNO= 5D: 
INS= 4D:  Search 5D; Stealth 4D.
PRE= 4D: 
HP= 90
Scale:  Heavy Vehicle
Length:  10 m
Height:  10 m

  • Parasite:  the Queen may release a tiny, insect-like parasite that will attach itself to an enemy unit and transmit all the unit sees back to the Queen.  The Parasite can only be detected by a close inspection of the infected unit (Moderate Difficulty).  It may only be removed with a Moderate Medicine: Surgery attempt or by killing the host.  A failed surgery attempt will also kill the host.  Recently, Terran physicians have developed a nano-technological antibody to destroy the parasite, but it is not yet commonly available (First Aid Difficulty 10 to apply).
    • Production Rate:  the Queen may produce 1 Parasite per 10 minute period. She may not create another until the first is released.  This rate may be halved with the Gamete Meisosis Evolution.
    • Parasite Lifecycle:  the Parasite must attach to a host within 5 minutes of its release, or it will die.  It cannot transmit images to the Queen until it has attached to a host. 
  • Spawn Boodlings (Spawn Broodling Evolution required):  some Queens may also spray enemy units with spores that implant themselves into animal tissue and metamorphose into a pair of ravenous Broodlings, dealing 7D damage (no armor protection permitted) to the host upon birth (the Broodlings will usually attack the host if it is still living when they are born).  The Broodlings may be evolved through the Flyer Attacks Evolution to deal 1D more damage to the birth host per Evolution.  Broodling spores only remain viable for 2D6 rounds once released.
    • Range:  3 / 10 / 25 / 40.  Strong winds may reduce the range of the spores. 
    • Armor Eating:  The spores will quickly eat through any inorganic material they come into contact with in order to get to living tissue.  They will reduce the Armor Value of a target by 4 per round for 2D6 rounds.  This value may be increased by 1 for each Flyer Attacks Evolution the Queen undergoes.  If the spores pierce the armor, they will infest the target.  If they fail to find living tissue within that time, they will die and become inert.
    • Production Rate:  the Queen may release the Spores no more than once every other round.
    • The spores will hatch within any animal tissue, including Zerg if they happen to attach to one.
  • Ensnare:  some Queens may eject an extremely viscous spraw of mucous that will hinder the movements of the strongest of ground units.  All movement rates of trapped units will be reduced by 10 m  (no faster speed is possible) for 2D6 rounds.  The Queen's web will ensnare friend and foe alike. The web's viscosity may be increased with the Flyer Attacks Evolution, further reducing the target's movement by 5 m per Evolution.
    • Range:  4 / 10 / 30 / 60
  • Infestation:  some Queens have become intimately familiar with Terran technology and have learned how to infest it with Zerg spores.  In doing so, the Queen turns the structure to the Zerg, infecting an humans within it.  These hapless victims are turned into mindless servants of the Swarm.
Armor:  30. May be increased by 6 per Flyer Carapace Evolution.
Movement: Atmosphere 30 m.  Space = 5
    Queens are a special breed designed by the Overmind to manage the complex functions of a large Hive.  Though they do not lay eggs, they can spawn Broodlings.  Queens are highly intelligent and show a viciously protective nature against any who would attack the Swarm under her care.  Like Overlords, they follow the Cerebrates and the Overmind without question.

Genus:  Unique Zerg strain.  Agent of the Overmind
CON= 13D. 
KNO= 8D: Tactics 9D; Sciences 10D; Sciences: Genetic Engineering 13D.
INS= 6D: 
PRE= 6D: Command 10D.
HP= 120
Scale:  Starfighter to Capital
Length:  10 m (rough approximation, of the "brain core" of the Cerebrate.  Cerebrates are usually incorporated into a larger bio-ship or structure).
Height:  10 m (as above)
Damage:  None.  Cerebrates direct minions to do their bidding and are usually protected by a multitude of the most elite of the Swarm.
Armor:  40. It is possible that the Cerebrate "brain" itself is not armored at all, but it will always be within a heavily armored shell.
Movement: NA
    The Cerebrates were created early by the Overmind to perform special functions for the Swarm.  Each Cerebrate exists for a particular purpose (to "defend the Hive", "explore for new species", "wipe out a new species", etc.)  Cerebrates have a high degree of indepedence and may establish bases and even carrry on military campaigns with little oversight by the Overmind. However, ultimately, all Cerebrates are genetically incapable of acting against the Overmind.  Yet, with time, each Cerebrate's degree of autonomy and self-awareness is going.  It is conceivable that some may develop different views of what is best for the Swarm and which path to take to genetic supremacy.  If such disharmony were to take seed within the Zerg, the results would be highly unpredicatable and undoubtedly bloody.

The Overmind
Genus:  Unified sentience of the Zerg
CON= 20D. 
KNO= 13D: Tactics 15D; Sciences 17D; Sciences: Genetic Engineering 20D.
INS= 9D:
PRE= 10D: Command 15D.
HP=  200
Scale:  Capital
Length:  NA.  The Overmind is housed within a massive bio-ship and exists in no single place.
Damage:  None.  The Overmind itself has no physical means of attack.  However, all Zerg are under its immediate and total control.  It is protected by the very best strains of the Zerg breeds.
Armor:  50. 
Movement: NA
    The Overmind was originally created by the Xel'Naga to serve as a semi-sentient collective consciousness of the Zerg.  Little did the Xel'Naga know how quickly the Overmind would expand its own self awareness and powers.  Within only a few years, the Overmind became highly intelligent and ruthlessly autonomous.  It soon developed the Cerebrates, assimilated all life on Zerus, and connived to incorpoescape its planetary cage to expand into the stars.  The Overmind turned its voracious horde on its Xel'Naga creators, destroying their world-ships and assimilating all their knowledge of genetic engineering and other star-faring races.  With that, the Overmind turned its attention to expanding throughout the galaxy and seeking out the its sibling race, the Protoss, for a final communion through their assimilation.
    The Overmind is single-mindedly dedicated to increasing the genetic perfection of the Zerg.  It has only noticed the humans because of their latent psionic potential and sees little other value in their meager genetic codes.  The Overmind's actions have increased the Swarm to millions of individual creatures, all of whom follow it without question.  Yet, there is some question as to whether it will be able to maintain control over all the Zerg spread throughout the galaxy as the Swarm continues to grow.  Of course, any genetic and behavioral abberations that might lead to too much autonomy among its servants will be met with swift annihilation.

After the Battle of Aiur (Broodwar Era):
     The Protoss hero Tassadar sacrificed himself to kill the Zerg Overmind Battle of Aiur, the Protoss homeworld.  This left many Zerg without direction, turning only into mindless beasts bent on slaying all other life.  The power vaccuum appears to have been filled somewhat by the more autonomous Cerebrates, Queens and Overlords.  It also appears that a former-Terran Ghost who was infected by the Swarm, known once as Sarah Kerrigan, has taken control of the Zerg as their new Empress.  Whether her control will be total, however, remains to be seen.