Typically in Call of Duty, the green guy is the dick who fools around and makes all of the teammates worse off. They often troll the team purposely, causing them grief and anger.

A term used to reference cannabis/marijuana/weed.

Green guys are your teammates in a Call of Duty game who are not part of your party: they show up as green triangles on the minimap, as opposed to party members who show up as blue triangles. In other words, green guys are pubbies who are probably useless if not actually a liability to you.

In reference to Call of Duty. These are players who are not in your party, and most likely random fools. They are the best players....... FOR THE OTHER TEAM. Usually the reason you are getting shot in the back, noob tubed, or killed by a killstreak, thank your local green guy.

green guys are probably aliens