Troops
As a Beast, you must face three types of COG forces. The Stranded, appearing only in the early waves, are the weakest—these are normal humans armed with simple weaponry. The second level consists of generic COG Gears. They are more dangerous than the Stranded, with greater health, better weaponry, and improved AI. The highest-level COG are the Heroes, better known to you as Marcus, Dom, Anya, Cole, and many others.
Heroes are special for two reasons: first, they always use a specific weapon (beware Cole’s Boomshot and Baird’s Torque Bow); and second, they always use Execution rules. This means that, to kill COG Heroes, you must first down them and then finish them off at close range. The only other way to dispatch Hero COGs is to kill them instantly with a lethal attack, such as a direct hit from the Digger.
COG Bases
In addition to the forces you face, COG personnel also have the benefit of fortifications, just as you do when you play Horde mode. Every round, a random control point is chosen as the COG base. You must assault it and defeat all of the COG forces present to finish the round. As the waves progress, the level of fortifications increases. That is to say, you generally encounter the same fortification positions at any given base, but their strength increases in the later waves.
The Silverback
The manned machine weapon that is the Silverback starts to appear around the fourth round, and occasionally two may appear in a wave. The Silverback is very dangerous when any COG soldier operates it, but it is extremely dangerous when a Hero is using it. Their increased accuracy makes the Silverback essentially a mobile turret.
The best way to deal with the Silverback is either to down its pilot with a well-placed grenade or flanking attack, or to destroy it from range without exposing yourself to its dangerous attacks.
