The origin of the term is commonly associated with the Battle of Belleau
Wood which took place in France during the First World
War. The Germans were shocked at the ferocity of the attacking
U.S. Marines (elements of the 5th and 6th Marine Regiments) and called them "Teufelhunde" which loosely translates to "Devil
dog". After the battle, the French renamed it "Bois de
la Brigade de Marine" ("
Wood of the Marine Brigade").
1. Commonly used to address another Marine and has no real negative connotations (unless spoken sarcastically, at which point the speaker is likely to spring a rather
nasty leak).
2. Used to address a Marine who's name is not known (before nametapes on the utility uniform became standard).