They are heavy assault soldiers of the 33rd Infantry that wear a menacing balaclava and large jury-rigged black armor cannibalized from ballistic and armor plates. They are typically equipped with an M249 SAW light machine gun, and two of them use AA-12 shotguns, which makes them 33rd's heavy hitters.
Fighting them head-on is ill-advised, as they can easily withstand high amounts of damage while also dealing out high damage themselves.
The best way to kill them is to take advantage of their slow speed and inability to take cover, such as pelting them with grenades, using blind fire, or concentrating fire on them via Squad Commands.
Heavy Troopers also have a long reload time with their M249 SAW, and as such is when they are most vulnerable. Their slow speed also makes them a prime target for sticky grenades.
- The Heavy Trooper wears an aviation helmet.
- Heavy Troopers can take the most damage before dying out of all the human enemies encountered in the entire campaign,
- Heavy Troopers are involved in multiple events that affected Walker's sanity, such as when a heavy trooper appears to begin teleporting while attacking Walker, and when Walker believes a heavy trooper to be Lugo.
- All Heavy Troopers are possibly officers, as they can be heard ordering their fireteams (or other nearby soldiers) to give them covering fire. However, it is possible that due to their vulnerability as a result of their slow speed and inability to take cover the 33rd simply has regular soldiers provide cover fire on request.