Grunt

These guys are here to clean up that little mess you made, and they aren't exactly happy to see you. Grunts are usually armed with a 9mm Assault Rifle and a healthy supply of grenades, but you'll encounter some packing shotguns, rocket launchers, or operating turrents. These guys aren't kamikaze morons; they're experienced troops. They'll work together to take you down. Listen to their radio chatter carefully, as their communications may contain clues.