Super Mutant Behemoth

Super Mutant Behemoths are giant Super mutants living in the ruins of Washington, DC. There are five in total, and they do not respawn after you kill them. There is an achievement/trophy in Fallout 3 entitled "The Bigger They Are..." obtained by destroying all five. These giant creatures are created by the Forced Evolutionary Virus (FEV).

Characteristics
Behemoths are huge Super Mutants, standing approximately three times as tall as a normal human. Some Behemoths carry fire hydrants that they use as melee weapons. They also wield car doors, which are used as shields. They have shopping carts on their backs as sort of backpacks, for carrying their victims with them like food rations.

Vault 87 Super Mutants become bigger and stronger the older they become after being exposed to FEV. Super Mutant Behemoths are the biggest super mutants in the Capital Wasteland which means they are also the oldest. Each Behemoth in Fallout 3 looks unique: some do not wear armor, some do not have weapons, etc. In addition, the five Behemoths vary in size; the GNR Plaza and Evergreen Mills Behemoths stand more than 20 feet tall, whereas the Behemoths in the Capitol Building and near Jury Street Metro are only about 12 to 15 feet in height, a little more than twice the size of a human.

GNR
The Behemoth right outside the entrance to the GNR Building is the easiest to find and is actually impossible to miss if you attempt Galaxy News Radio (quest). You will have ten Brotherhood of Steel members to back you up, though they are not invincible and some may already be dead or die in the process. On a nearby fountain in the square, you will also find a dead BoS member slumped on the fountain's rails in an almost picturesque position. The soldier will be in possession of a Fat Man and some Mini Nukes, which will be invaluable in bringing down the monster. However, keep in mind that the dead soldier will not be there if Sentinel Lyons isn't present in the battle. Sometimes the Behemoth may be stuck in the pile of rubble on the west end of the GNR plaza, and is unable to move or attack. This makes it much easier to kill. Also, sometimes grenades can cause him to be stuck in the air, making the fight easier since he cannot move or attack. Also, if you use the building you have to go through on the way to the plaza, it can be used as the perfect cover from it. Just sit inside and throw grenades from the doorway until he dies because he can't hit you if you're properly inside.

Evergreen Mills
In Evergreen Mills, the raider-controlled train yard, a Behemoth has somehow been captured and imprisoned by an electric fence. However the fence's power source is simply a nearby generator. When approaching the area from the south, the generator can be easily destroyed with any rifle (it should be noted that there is a switch to turn off the electric fence right next the generator as well);. Once the electric gate is turned off, the Mutant will rush outside and attack the Raiders, killing most, if not all of them (most of whom are armed with nothing but 10mm Pistols, dependant on level); still, their sheer numbers should be enough to take it to within a few bars of its life. Because of the gate that traps this monster, the raiders that occupy the train yard, and the cliffs that surround the area, the number of methods to deal with the Behemoth are almost endless. It is possible to have the Behemoth follow you out of Evergreen Mills. If you lead him to the Jury Street Metro directly east and trigger the Behemoth encounter there, they will begin to fight each other. The one with the fire hydrant will most obviously win.

Capitol Building
A Behemoth can be found in The Capitol Building fighting Talon Company mercenaries at the west entrance. There is a considerable amount of fighting between Super Mutants and Talon Company so it's possible to sit back and watch the fun. You can also find a room next to the dome with the Behemoth containing a computer which, when hacked, will allow you to activate the turret system in the dome. There are several turrets that are activated by this command, so it'll likely make things much more interesting. One of the Talon Company mercenaries is equipped with a Fat Man and a few Mini Nukes as well, which makes them fully capable of killing the Behemoth. Keep your distance from the room where the fighting is going on as you can easily be caught in the blast radius of the mini nuke or possibly be targeted instead of the Behemoth.

Takoma Industrial
A Behemoth and several Super Mutants are located northeast of the Takoma Park in Takoma Industrial. There is a truck near a water tower a few feet away. On the truck you can see a dead mercenary and a switch that activates some artillery that makes the fight much easier. This artillery will break after a few shots and need to be fixed with a Science skill of at least 33. After fixing it the artillery won't break anymore, so you can kill the Behemoth without using any of your ammo. But if you want to kill it with your normal weapons, and if you don't want the Behemoth getting too close, you can fire the artillery and it will walk toward where the artillery shell hit, and it will completely forget about you.

Jury Street Metro Station
This Behemoth is located at a Super Mutant camp, marked by a group of wrecked train cars west southwest of Jury Street Metro Station. On these tracks are several overturned railway carts. One of them is a large empty storage container, with the open part facing the Jury Street Metro area. In this container are several "Cart Cages" (shopping carts pushed together to make a cage). One of these contains a teddy. Open the cart and the Behemoth will come for you. When he spawns, the Behemoth may get caught up fighting Talon Company/Regulators (depending on Karma)/other creatures near the Jury Street Station. Although, on odd occasion, the Behemoth will appear before opening the cart.

Its been known that if you open the cart cage and let it respawn then load the game and go back to Jury Street Metro Station it will be waiting next to the cart cage.(Unconfirmed)

Appearances
Super Mutant Behemoths appear only in Fallout 3.

Behind the scenes

 * The word Behemoth means "a huge or monstrous creature." It comes from the Book of Job in the Hebrew Bible.

Videos

 * Behemoth at GNR (in HD): http://www.youtube.com/watch?v=rTZVrHEneG4
 * Behemoth at Evergreen Mills (in HD): http://www.youtube.com/watch?v=TbW4VJajdmE
 * Behemoth at Capitol Building (in HD): http://www.youtube.com/watch?v=TayUq2hadiI
 * Behemoth at Takoma Park (in HD): http://www.youtube.com/watch?v=8WrjFAgC6Lc
 * Behemoth at Jury Street Metro Station (in HD): http://www.youtube.com/watch?v=Lye4wOg6F8s

Supermutant - Behemot Супермутант-бегемот