Super Mutant (Fallout 3)

Vault 87 super mutants or East Coast super mutants are the variant of super mutant found in the Capital Wasteland.

Background
These super mutants were created in the "Evolutionary Experimentation Program", the experiment assigned to Vault 87. The modified strain of FEV used to create these mutants resulted in a new strain of super mutant which, in addition to becoming sterile, grow larger and stronger as they age.

The first super mutants of this variety were created in 2078, becoming a permanent feature of the Capital Wasteland. Too dumb to overrun it, but too strong to die off.

Biology
They differ from their Western counterparts in that they possess a yellow-green skin color, and are generally less intelligent and more aggressive. They also appear more healthy, as they are never seen with any cybernetic parts or organic disorders. However, unlike their distant cousins they retain less of their humanity after transformation, and no distinguishing features from their former lives can be found. Every super mutant's facial expression is permanently set in a sneer.

During exploration of Vault 87, information from terminal entries reveals more about the process that humans go through to become super mutants. When exposed to the specific strain of FEV found there, muscular and skeletal systems develop rapidly, while mental faculties diminish. Most sexual characteristics are eliminated, transforming the subject into an almost asexual state.

Despite their apparent lack of intelligence, the mutants are somehow able to organize themselves into a coordinated army (as evident from numerous raids). They have also procured large amounts of advanced weapons, ammunition and equipment, and maintain the FEV infrastructure necessary to transform humans to increase their numbers. How they are able to achieve these things is never explained, as the player never meets a mutant leader or governing body in the game, unlike in previous Fallout games.

In the ruins of D.C., the super mutants are looking for human captives in order to expand their army, as well as a new source of FEV; as a conversation between two super mutants in Vault 87 reveals that they are running out of "green stuff".

Also, as Fawkes demonstrates when retrieving the GECK in Vault 87, they are highly resistant to radiation.

Gameplay attributes
Despite their seemingly low intelligence, super mutants can sometimes employ effective military tactics. Melee-armed mutants will move in to engage the player while those behind them take pot-shots with ranged weapons. Super mutants armed with grenades will often use them without regard for any fellow mutants that might be caught in the blast radius.

When encountered at lower levels, super mutants are usually in groups of two or three, accompanied by one or two centaurs. At higher levels they can be found in groups of three to five, with a few centaurs acting as their watch dogs.

Super mutant
These are the youngest and weakest of the Capital Wasteland super mutants. They are usually encountered in groups of two or three, led by a stronger super mutant. Regular super mutants have almost twice as much health as most standard human non-player characters, but this is somewhat offset by their lack of body armor. Some of their prime locations are the GNR Building Plaza, the National mall, the Capitol Building, the Statesman Hotel, the National Archives, and Falls Church. They can also be found aboard Mothership Zeta in stasis chambers. Freeing them will cause them to become hostile.

Super mutant brute
Super mutant brutes are stronger and tougher opponents than regular super mutants, as they are better armed and armored. They are the most common of all super mutants once the player reaches a high enough level, and are easily distinguished by their galea-like metal helmets and crude metal armor.

Super mutant master
The super mutant masters are considered the group leaders of the mutant bands which plague the Capital Wasteland. They have more Hit Points than most "common" super mutants. They are discernible by their armor, which appears to consist of what resembles black tubing that wraps around their lower and upper body and something like a fighter pilot helmet. A gas mask is strapped to their left shoulder, possibly acting as a makeshift pauldron. They are generally never alone and are usually accompanied by one or two brutes.

Super mutant overlord (Broken Steel)
The super mutant overlords are variants added to the game in Broken Steel. They are aged, even more powerful than super mutants masters, and much harder to bring down. Super mutant overlords appear to be evolving into behemoths, and are about half-way between the normal super mutants and behemoths, size-wise. Their intelligence (in comparison with other types of super mutants) is questionable, but they are smart enough to wield energy weapons with some degree of skill. Sometimes, they are seen leading groups of other super mutants, although they are more frequently seen in pairs, if not alone completely. Overlords also have a 40 unblockable damage bonus when attacking with a tri-beam laser rifle and a 25 damage bonus when attacking with a special version of a super sledge. When carrying an assault rifle or a Chinese assault rifle, they use a one-handed pistol animation. They have a good chance of dropping above-average loot such as stimpaks, mini nukes, and purified water. They appear frequently at later levels. One will appear the first time the player travels to the GNR Building.

Super mutant behemoth
Towering at about 20 feet tall, the behemoths are the greatest threat among the East Coast super mutants. There are only five of these behemoths, although reports of their sightings continue long after the last of them is killed. They are the oldest and strongest of their kind, as well as being many times larger than any other humanoid creature. For unknown reasons, they will not speak, instead they will make monstrous roars. They are usually armed with almost unrealistically large fire hydrants mounted on a large pipe; other than that, they also use their enormous fists. Either way, both weapons are heavy-hitters, and will cause major damage against any enemy smaller than them.

Killing all five behemoths will grant you the achievement/trophy, The Bigger They Are....

The Evergreen Mills Behemoth remains in the game files of Fallout: New Vegas. However there is no texture.

Notable super mutants

 * Fawkes
 * Uncle Leo

Appearances
Vault 87 super mutants appear only in Fallout 3 and its add-ons Broken Steel and Mothership Zeta, but only in its cryo lab.

Bugs

 * Occasionally, super mutant brutes, masters and overlords may appear merely labeled as a "super mutant", but still have the same health and equipment of brutes/masters/overlords.
 * Super mutants may not acknowledge the player no matter how close he/she gets to it.