Boomers are huge, unintelligent Locusts. They usually wield the Boomshot grenade launcher when in combat, though Boomer sub-classes generally wield other weaponry and are often partnered up with other Boomers. They do not use infantry tactics unless instructed by a more intelligent superior, instead moving forward slowly whilst firing their weapons. To combat this tactic, many Gears have noted that an easy way to defeat a Boomer is to stay behind cover and bring them down with automatic fire. Boomers mainly can be heard laughing and saying "Boom!" before they fire, and referring to the incoming mortar rockets as "Sky Fire."
Just as typical Locust drones are divided into sub-classes such as Grenadier and Sniper, Boomers also have their own sub-classes, though theirs are easier to distinguish.
- Butcher - These Boomers wear black aprons and will try to rush enemies with their large cleavers. These are the weakest of the Boomer sub-types.
- Grinder - These hulking freaks carry Mulchers: large miniguns that can cut down swaths of human combatants easily. The best means of fighting Grinders is to surround them in open areas, so long as there's cover to hide behind. The Mulchers will overheat after firing for so long, so the cooldown period is the time to strike.
- Mauler - These brutes wear horned helmets and carry Boomshields that can block any kind of firepower, short of an orbital strike anyway. Like Butchers, they do not use ranged weapons and carry large flails. The Mauler's flail has an explosive impact, so it does not even need to hit an enemy directly to kill them.
- Flamer - Flame Boomers are armed with Scorcher flamethrowers. They wear less armour than other Boomers which allows them to move slightly faster, but they come with an obvious weakness: the fuel packs on their backs. Shooting a Flamers fuel pack will rupture it and cause it to explode, so it is best to save ammo by aiming for the fuel pack rather than shooting the Locust itself.