Elites are human heavily armed human units (not zombies) which have been trained to work with the zombies, so they dont know that the zombies are working for Sam they just know that their objective is to kill any forms of resistence (which in this case to them isn't zombies) at the end of a round they drop an lmg which a player can pick up, and max ammo, and a fire sale, the fire sale however, is extended from just thirty seconds, to a minute and a half. The elites will disable traps and lightwait elites will have a 50% success rate at dodging traps like the large saw.