From EA Official site. "Fight savage beasts and ruthless marauders." Are the Scars the marauders or indigenous creatures that are intelligent enough to use our technology? In the Gameinformer article describing the E3 trailer the Scars were referred to as "lizard foes". Their speech pattern could represent some sort of reptilian language. But they could also be some sort of insectoid. They attacked the large walker (there must be a name for it) and proceeded to scavenge parts or cargo. They do seem to be light to medium armored and have the ability to use a exo suit (a heavy). The images below hopefully will give you a chance to determine what they are.