The Corrosive Germ Colony is the Zerg structural means of aerial and static ground defense. Able to fling Germcloud Spores (a corrosive variation of Creep) high into the atmosphere, Germ Colonies can quickly ravage any incoming enemy air force. In addition to its anti-air capabilities, the Germ Colony also serves as a stationary ground defense against any incoming enemy units thanks to using an explosive variant of Germcloud spores that remain earthbound due to their weight, the Germ Colony can quickly turn the tide of a battle.
The Corrosive Germ Colony may move on crab-like legs outside of the boundaries of Creep, but like other Zerg structures will slowly degenerate and eventually die if it remains outside of the boundaries for too long. Germ Colonies cannot be planted outside of the Creep.