Used during vietnam, Charlie was coined zipperheads because of the way a head looked after it had been hit with a high powered automatic weapon. The the typical rising machine gun would cause a face wound that looked like an open zipper on the face of some one from the viet kong.

Word commonly used in the Vietnam war to describe a person whos eyes look asian, or slant. As in you could zip there face up. Also see gook which is another term to describe asians.