Theron Guard

Biography
The Theron Guard represents the elite of the Locust, head-and-shoulders above the lowly Drones in terms of equipment, intelligence, and training. They are elite Locust, assigned to commando-style raids against high-profile targets and high-level defensive missions that require the sort of precision the Therons possess. If the Drones and Boomers represent the Locust military's hammer and anvil, then the Theron Guard is most decidedly its scalpel. (From Gears of War Wiki)