The Zerg Swarm is controlled by the Overmind, a massive living brain.

Tassadar crashes his flagship, the Gantrithor , into the Overmind, channeling both Light and Dark energies to destroy it. Aiur is left in ruins. Episode IV: The Resistance (Brood War)

Kerrigan stands atop the Zerg hierarchy, the most powerful being in the galaxy, while Raynor vows to one day take her down.

Kerrigan betrays everyone to ensure she is the sole ruler of the Zerg.

Once the UED is weakened, Kerrigan kills Fenix (Protoss) and Duke (Terran).