Super mutant overlord

Super mutant overlords are a type of Vault 87 super mutant. They are evolutionarily somewhere between super mutant masters and super mutant behemoths.

Characteristics
Normal:

Tri-beam Laser:

Super mutant overlords are some of the toughest enemies in Fallout 3, wielding powerful weapons and possessing 2.5 times as much health as a deathclaw or sentry bot.

Weapons
Overlords carry gatling lasers, missile launchers, tri-beam laser rifles, and super sledges as standard weapons. In a rare case, you may find an Overlord with a minigun, assault rifle, AER9 laser rifle, or Chinese assault rifle. Sometimes, like in Germantown Police HQ, one may be found carrying a hunting rifle but not using it since he can't, instead he will just use his fists.

If an overlord picks up a rifle normally used by other mutants, such as a Chinese assault rifle, they will use only use one hand to fire it.

It appears that they are most commonly equipped with tri-beam laser rifles as ranged weapons, this can be problematic (especially on higher difficulty levels) since they inflict an extra 40 damage per shot even if you have 85% damage resistance they can still knock off roughly 25% of your health (assuming you have nearly 600 hp) making overlords exceptionally deadly with this weapon.

Locations
Super mutant overlords can be encountered anywhere where regular super mutants appear usually at high levels, but can be found at low levels at some places, like outside the Citadel, Germantown Police HQ, and the Museum of Technology. Overlords can also spawn in Bailey's Crossroads in Operation: Anchorage and the Cryo Lab in Mothership Zeta ,and GNR Building Plaza . Overlords also become more common the higher the players level.

Appearances
Super mutant overlords appear in the Fallout 3 add-on Broken Steel.

Bugs

 * During "Big Trouble in Big Town" is where this happens most often: Sometimes, Overlords and Masters (the only two confirmed) will appear as simply "Super Mutant". They still have the same Health and Characteristics as an Overlord/Master, however they may not have the usual Overlord/Master Inventory (they may have Dog/Ant Meat like a typical "Super Mutant" would). When this happens you may also notice that Overlords may not have their signature weapons, but instead they may possess a Hunting Rifle (which is not wieldable by Overlords therefore they will attack you with their fists) or a Chinese Assault Rifle (Overlord wieldable, they only use one hand to fire it). This has not been confirmed with "Super Mutant Masters"
 * If you shoot the weapon out of a super mutant overlords hand whilst accompanied with a follower they will often run around in confusion searching for a new weapon, though with the follower it seems the NPC becomes confused and continues to run around in loops completely disregarding your character. This may be used to the players advantage.