Carrion wasps are a species native to Cruxas III. They appear to live up to their namesake, feeding on the bodies of fallen creatures.
During the Second Great War, the essence of the carrion wasps was assimilated into the Zerg Swarm. Through this, the zerg were able to develop the carrion swarm host strain.
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Carrion wasps appear in the Swarm Host Evolution mission of Heart of the Swarm. They are critters, and do not fight back.
They use the same unit portrait as the locust.