Ruin smoke and retch cloud

Ruin smoke and retch cloud is a Yavaun Critter unit in War Wind.

Background
Believed to have been created as a byproduct of chemical experimentation by Tha' Roon biolusion in the breeding pits, this has yet to be proven either by myself of my colleagues. Still others who are superstitious maintain that they are the spirits of the dead who have returned to exact vengeance on those who have wrong them, while others maintain that they are extensions of a giant invisible entity that is feeding on the land whatever the case maybe, the different hues and colours of these cloud-like forms are the only means of distinguishing their powers and characteristics. The Ruin Smoke has an acidic nature which damages or corrodes those buildings and vehicles that it can cover with its oily mass, and the Retch Cloud exudes a deadly poisonous gas that destroys living organic tissue. Their nature is indeterminate, only that they cause terrible ruin and destruction as the flow about slowly and at random, appearing and fading unexpectedly, following their own mindless whims.