The Devourer is available to the Zerg Swarm in the same way the Guardian is obtained. It is the Zerg anti air unit found in the Brood War expansion pack. Since Mutalisks were not very effective against powerful air units and Scourge had limited use, the Devourer solves all of the Zerg air problems.

Devourers hit for decent damage, but they attack very slowly and have one of the longest attack cooldowns in the game. However their attack will also leave Acid Spores on the target. Note that the damage portion of their attacks will not splash to other enemies, but the Acid Spores will splash to nearby targets. The spores will stack up to nine times and will last for a while. Acid Spores will reduce the enemy Armor causing all attacks against that target to be increased equal to the number of spores. These Spores can be considerably deadly when combine will other splash attacks such as the Mutalisk. Normally the last hit of the Mutalisk does 1 damage but if the target has 9 Acid Spores, that hit will be bumped up to 10, a considerable difference. The Acid Spores will also increase the time between attacks.

While Devourers are good to have against any air fleet, they excel at taking down high armored units, such as Battlecruisers. This enables support units with weak or multiple attacks, such as Hydralisks and Mutalisks, to greatly increase their damage output against such heavy armored targets.