The Anti-Air Units are a branch of Big Green's military that defends the base from direct attack. This typically means attack from the air, though they have also defended against other attacks. They are led by the Air Defence Captain.
The Anti-Air Units employ calabash-based cannons not unlike those used by the tank army. However, they are stationary, being fixed to the base, and pivot to target. The cannons are normally concealed, retracted within Big Green base, but in battle are activated. Cannonballs are launched by the gunners punching them into the cannonbarrels from within, while strategy is coordinated by the Air Defence Captain.
The Anit-Air Units were featured most prominently in The Air Battle, when they were called upon to stop the advance of the eagles. Their cannons, however, failed to hit the agile eagles, and Lin Chung was called upon as a sharpshooter. Though he demonstrated the ability to hit the eagles, he was disarmed by the Anti-Air Units, who found his bamboo ammunition tasty. After Mighty Ray and Mystique Sonia managed to daze the eagles, the Anti-Air Units found themselves able to finally hit their foes, which rendered the eagles featherless and bald.