Overmind (Starcraft)

From Multiversal Omnipedia

The Overmind was the final creation of the Xel'Naga, the Overmind was made to control the Zerg swarms. (It refers to itself as the "eternal will of the swarm.") Its goal was to assimilate the Protoss into itself, thus uniting the two halves of the Xel'Naga's creation. According to the Overmind, the Protoss were gifted with a purity of mind, while the Zerg were blessed with a purity of essence.

The original Overmind was destroyed by the Protoss (specifically Tassadar, who crashed his ship Gantrithor into the entity). A second Overmind was nearly formed by surviving Cerebrates on Char, but it was subdued (while still immature) by the UED, using psionic-dampening drugs. However, Kerrigan was able to invade Char and destroy the fledgling Overmind, assuring her rule of the Zerg swarms.