These units are similar to Guardians according to their root organisms.They are morphed from mutalisks.These units are designed in Starcraft Brood War.These units have only anti air weapon that means they can not attack ground.The Devourers special chemicals slows down the enemy units.The devourers are superior against light enemy units also their carapce is very thick which protects them from any threat easily.The speed of the Devourer is good which makes it very efficient but the cost is high and the place in the tech tree is far like Guardians.