Siege Tank - Zerg - Appearances

Appearances

In StarCraft, the Zerg are obsessed with the pursuit of genetic purity, and are the focus of the game's second episode. With the Xel'Naga–empowered Protoss targeted as the ultimate lifeform, the Zerg invade the Terran colonies in the Koprulu Sector to assimilate the Terrans' psionic potential and give the Zerg an edge over the Protoss. Through the actions of the Sons of Korhal, the Zerg are lured to the Confederate capital Tarsonis, where they capture the psionic ghost agent Sarah Kerrigan and infest her. Returning to the Zerg base of operations on Char, the Zerg are attacked by the dark templar Zeratul, who accidentally gives the location of the Protoss homeworld Aiur to the Zerg Overmind. With victory in sight, the Overmind launches an invasion of Aiur and manifests itself on the planet. However, at the end of the game, the Protoss high templar Tassadar sacrifices himself to destroy the Overmind, leaving the Zerg to run rampant and leaderless across the planet.

The Zerg return in Brood War initially as uncontrolled indiscriminate killers. Through the early portions of Brood War, Sarah Kerrigan is at odds with the surviving cerebrates, who have formed a new Overmind to restore control of the Swarm. Through allying herself with the Protoss, Kerrigan strikes at the cerebrates, causing disruption of their plans. Eventually, the UED fleet takes control of Char and pacifies the new Overmind with drugs, putting the cerebrates and most of the Zerg under their control. Kerrigan retaliates by allying with the Dominion and the forces of Jim Raynor and Fenix, regaining the ground lost to the UED. However, she later betrays this alliance, dealing long-term damage to her allies' infrastructures. Proceeding to blackmail Zeratul into killing the new Overmind, Kerrigan's forces destroy the remnants of the UED fleet, giving her full control of the Zerg and establishing the Swarm as the most powerful faction in the sector.

In StarCraft II: Wings of Liberty, Jim Raynor and the rebel forces who oppose both the Dominion and the Zerg, manage to secure an ancient Xel'Naga artifact and after successfully infiltrating Char, they use it to subjugate the Zerg and restore Kerrigan's human form. Once again without a unified leadership, the Zerg get divided into multiple broods feuding over control of the Swarm. This situation persists until the events of StarCraft II: Heart of the Swarm. Kerrigan, believing Raynor to have been killed in a Dominion surprise attack, becomes the Queen of Blades again, but this time she is no longer motivated to destroy humanity.