Nam War

Marines in Vietnam would often try to recruit locals to help guide them in their area of operations. In some areas, however, the locals were fearful of going into the densest, darkest parts of the jungle. The reason, they found, was the local superstition that phantoms, called ma, occupied the trees there.

Montagnards warned the U.S. troops that reanimated corpses awaited them in the trees. The Marines, of course, shrugged the stories off as folklore.

Starting in 1965, it became very real. American troops in the jungles of Vietnam began reporting ghostly figures moving supernaturally through the trees. Others reported fanged creatures with black eyes that would try to kidnap and consume unsuspecting troops. In one encounter, the beasts were found to be bulletproof.

It didn't matter what time of day it was, the corpses lived by both day and night. Since the triple canopy jungle kept the sunlight from hitting them, the military's top brass decided to get rid of it.

That's the real reason the military developed Agent Orange and napalm. The Marines would then roll in with flamethrowers to finish the job.