The nature of Rubybrood Zergs is their power hides in fire, blood and iron, making a red triangle of the Zergs. Therefore, their evolution chamber is partly a foundry.

Blood Pond is Rubybrood Zergs fusion of Spawning Pool and Hydralisk Den. Due to already accelerated evolution, Rubybrood Zergs create their units without need for Larvas. That's how Rubybrood Zerg Hydralisks comes straight from the Blood Pond fully developed already.

(Zerg Evolution Chamber, Spawning Pool and Hydralisk Den belongs to Blizzard)