Broodmother

Brood mothers are powerful s, tasked with guarding and leading various broods.

History
Brood mothers fill a role similar to cerebrates. The cerebrates were tainted by their ties to the Overmind, according to Infested Kerrigan, so she instead created unique queens with personality and intelligence between the and Invasion of Char. These queens were imprinted with overriding directives to be strong and evolve, and believe that the strongest are meant to rule.

Kerrigan's control over the Swarm was broken at Char, and the brood mothers took their broods away to hide in the Koprulu Sector, still following their instructions. The brood mothers wouldn't follow Kerrigan, as they felt she was weak. Kerrigan began tracking them down and proving her strength against them.