"First seen guarding the Imulsion pumping station while the Gears traversed The Hollow, Theron Guards are much tougher members of the Locust. They are among the higher and more elite ranks, taking on roles such as field commander. They are stronger, faster, more tactical, and deadlier than any other Locust previously encountered. Therons are the only known Locust species to carry more than one weapon. They will switch accordingly, such as between Lancer and Gnasher in different situations. All Therons also carry Boltok Pistols, but only use them when you are too close to target with their torque bow. Their favored and most often wielded armament, however, is the infamous Torque Bow and should be taken with extreme caution. They aim extremely well with any weapon they use, including the Torque Bow. They are easily distinguished from Drones as they wear long, red, leather-like coats that trail behind them as they move as well as metallic masks. Their sibilant voices have been known to scare Gears into fleeing.
Therons are far more intelligent than other species of Locust infantry. Most other soldiers like Drones and especially Grenadiers will not use cover and simply run straight at the enemy. The Therons, however, will retreat if they are taking too much fire, and you should not fall for their tricks.
Theron Sentinels are similar to standard Theron Guards, but have a few minor changes. They are slighty taller and almost aways are armed with the Torque Bow, more often than standard Therons. They wear a full-head helmet with a narrow visor along it. There appears to be no strength or tactical differences to other Guards."
-COG Intelligence Databanks