Super mutant overlord

The  is a type of super mutant added to Fallout 3 by the Broken Steel add-on. Bethesda revealed that they are evolutionarily somewhere between Super Mutant Masters and Super Mutant Behemoths.

Characteristics
Super Mutant Overlords are some of the toughest enemies in Fallout 3, wielding powerful weapons and possessing 3 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.

If an Overlord picks up a rifle normally used by other Mutants, like a Chinese Assault Rifle, they will use only 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.

Appearances
s appear in the Fallout 3 add-ons Broken Steel and Mothership Zeta.

Locations
Super Mutant Overlords can appear anywhere where regular Super Mutants appear.