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. On all versions of the game, there is an achievement/trophy entitled "The Bigger They Are..." obtained by destroying all five. These giant creatures are created by the Forced Evolutionary Virus (FEV).

Characteristics
Super Mutant Behemoths can be very difficult to kill, as they are the most resilient enemy in the game. But usually when you encounter them, they are being fought by a certain group such as the Talon Company, Enclave Soldiers, or Raiders. These groups of soldiers will usually pack a punch on the Behemoth, knocking off a good chunk of health for you to finish him off. Take a look at the Strategies section for information about how to kill these giant beasts. It is unknown what causes Behemoths to be formed.

Appearances
The Behemoth appears only in Fallout 3. A robot also named Behemoth can be found in Fallout Tactics.

Actual Size
When initially designed Behemoths may have been smaller, about half the size they are now. The skulls, car doors and fire hydrants they carry are all bigger than any skull, car door or fire hydrant in the wasteland. This is evidence that the Behemoth's size could have been increased after creation. If you spawn a Behemoth they are not the size encountered in-game. Rather, they are only slightly taller than Fawkes.

Physical Appearance and Equipment
Behemoths are roughly 20 foot tall 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. They also can slap you lol

Strategies

 * Behemoths are usually supported by normal Super Mutants. Give the guards priority, but keep moving to avoid being hit by the Behemoth. The Behemoth that appears at the GNR station, however, appears to have invoked hostility from all nearby Super Mutants, so it might be better to shoot these Super Mutants later.


 * Due to their large size, it is relatively easy to achieve head shots in VATS. If the player has sufficient first-person shooter experience, it is also not too difficult to achieve head shots without VATS, assuming the gun that player is using does not have significant spread.


 * Due to their large size, Behemoths cannot enter hallways or get under low hanging rubble and have difficulty getting around any large obstruction. The player can use terrain to their advantage to keep themselves out of melee range while gradually taking the Behemoth down at a safe distance.


 * An all purpose strategy for any ranged player is the Dart Gun which will cripple the Behemoth's legs with a single shot regardless of the player's Small Guns skill. With the Behemoth's mobility reduced practically any ranged weapon can be used to finish it off. A crippled Behemoth can still deal massive damage if allowed to get into melee range.


 * Small Guns are highly ineffective unless aimed at the Behemoth's head. However, a Chinese Assault Rifle in good condition works fairly well, and can bring down a Behemoth with a handful of mags worth of full auto fire. Keep backing away from the Behemoth while emptying your gun into it. Don't use VATS as it makes you stand still for a second or two after firing. Small Guns specialists will find the Victory Rifle also efficient and capable of knocking a Behemoth down.


 * The Alien blaster and Firelance are particularly useful against Behemoths. With the quick rate of fire and high damage, a skilled Energy Weapons character can take one down before it can get close enough to do any damage.


 * Big Guns specialists with a rank of 100 can do 1674 damage per shot with a perfectly repaired Fat Man, and it also has a potential to knock a Behemoth down. Using one Mini-Nuke and following up with the Minigun while the Behemoth is staggering is a quick and effective strategy. The Missile Launcher is also quite effective, and a direct hit to the head with a missile can knock off a decent chunk of its health, even if the launcher is in poor condition.


 * Laying land mines and luring the Behemoth through them is an effective strategy should the player be low on ammo on every weapon. Bottlecap Mines in particular are great because of their high damage.


 * An Unarmed specialist can also fight them barehanded, though only after dosing on as much chemical assistance as possible. Behemoths are susceptible to knock-down criticals, though targeting their towering heads outside of V.A.T.S. is much more difficult. Targeting arms for critical strikes can reduce their impact and effectiveness. On Hard difficulty, well-timed and frequent stimpack use will be needed to survive the brawl. This is not suggested; similarly, very hard will require near perfection if the player chooses to take on a Behemoth barehanded.


 * If Dogmeat is still traveling with you, order him to stay in a safe place. Dogmeat's only attacks are close range melee and he can be damaged quickly by the Behemoth. This can be dealt with somewhat with the dialogue option to use a Stimpak, which is available even during combat, but keeping Dogmeat out of melee range is safer. This advice actually is also good for any NPC followers you might have, since they will often just stand in place attempting to fight the behemoth.


 * The Terrible Shotgun is particularly effective against the Behemoth as its large size makes getting the entire spread of buckshot on-target relatively easy. If staying that close to the Behemoth is too daunting, bring a companion, preferably one equipped with T-51b Power Armor, to act as bait while the player rapidly unloads shells into the beast's back. Like suggested above, bringing a companion isn't always the best idea.


 * One of the best (and probably the most wasteful) ways to kill a Behemoth is to use the wicked power of the Experimental MIRV and kill the Behemoth in one hit.


 * With the Scoped Gauss Rifle, 10 Luck, and both Finesse/Survival Guru perks, it is possible to score a 90% critical hit. These critical hits will knock down a behemoth rather easily. Using the Gauss Rifle to hinder it, it'll only take between five or ten shots to defeat it.

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 most will likely be killed quickly. One of the Brotherhood members is in possession of a Fat Man weapon and will die quickly, before having a chance to use it. The lamppost in the area is fragile-looking, but the Behemoth considers it a wall, and it can serve as effective cover from the Behemoth. If you have trouble defeating this behemoth it’s possible just to run to door of the GNR building. There is a back exit to this building so you will not have to face him on the way out. Also when you quick travel back to this location you will be placed behind the sandbags pretty much out of harms way near the door. Another possible strategy is to take cover under the GNR building, coming out when your AP recharges to use VATS.

If you do not need to do the GNR quest (e.g. you went straight to Rivet City), you may find on arrival at GNR the Super Mutant Behemoth will smash down a wall nearby and "break in" to the square, attacking you.

Also, if you did skip the Following in His Footsteps Quest and have already located your father, you will need to fight all of the Super Mutants alone up until you are in front of GNR. Then a few of the Brotherhood will be fighting the remaining Super Mutants. The Super Mutants will win leaving only two or three left. As soon as you leave the building you are in, the explosion will trigger and the Behemoth will appear. If you retreat to and stay in the building, you can slowly hurt him because he cannot enter this location.


 * I learned Dad's location from Rivet City before heading to GNR. When I arrived at the plaza, I carefully entered the area. When the explosion signaling the Behemoth happened, I darted inside the school building, planning to kill it from there, but the Behemoth was nowhere to be seen.

Evergreen Mills

 * In Evergreen Mills, the Raider-controlled train yard, a Behemoth is trapped by an electric fence. When approaching the area from the south, the generator can be easily destroyed with any rifle; a melee will ensue in which most of the raiders will die killing the Behemoth. However, no experience will be gained by this method. The easiest method of legitimately defeating the Behemoth is to clear the area of raiders, lay several Bottle Cap Mines near the gate (but far enough away from the generator so they don't detonate when it explodes) and then release the locks on the cage. Alternatively, the Behemoth can be attacked by ranged weapons through the mesh gate while the generator is still active. The roof of the nearby train car offers a clear view of him.  However, it is possible that the Behemoth may escape during the player's shootout with the Raiders, forcing the player to deal with him in the tight confines of the camp.  Another alternative is to jump between the carriages to get to the other side of the carriages.  The Behemoth will try to get through but can't and eventually will run off.  Just jump back over and it comes back, repeat until the Behemoth dies. Normally the Behemoth won't attack any followers with this method. Another method is to simply stand on the carriages and shoot the encaged Behemoth from a point that means you shoot over the walls.  Glitch:  If you approach the cage and go into VATS with a frag grenade, while the Behemoth is still locked inside, there is a chance to send it shooting into the sky which will kill it before it lands.

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.
 * A very simple tactic for defeating this Behemoth is simply standing just outside the doors leading to the room which he is in. Being that he cannot fit through the doors, and has no projectile weapons, he will simply try his best to back away from the doorway allowing you to injure him from afar. If he gets too far away, simply walk into the room and allow him to run at you, then move back through the doorway when he gets close allowing you to continue hitting him until he dies. You can even have fun taunting him, or killing him with a weak weapon just for kicks

Takoma Park

 * A Behemoth is 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 a lot easier. This artillery will fire several times before breaking (you can fix it with a Science skill of 33).

Jury Street Metro Station
Note: You can wait up on the edge overlooking the train carts and wait 12 hours and the behemoth will appear, but sometimes Enclave soldiers may appear as well. They will ally with you against the behemoth but once he dies they turn on you. Fawkes can be helpful here as well.
 * One final Behemoth is located at a Super Mutant camp, after following a series of search party notes (Unmarked quest: Searching for Cheryl). The final note takes you to a camp between the Jury Street Metro Station and Evergreen Mills. Both are located due west of Vault 101. You do not need to get these notes to make this Behemoth appear. Keep going west from Vault 101 until you find Jury Street Metro Station. Head further west from there until you find a bunch of wrecked train cars along with a few Super Mutants. If you're having trouble finding it follow the tracks heading NE from Evergreen Mills, or you can just look for the train tracks SW of Jury Street Metro (hint: they come out of a tunnel in the hill). 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 grab the teddy. It is not necessary that you take the teddy, because simply standing next to the cage and waiting will cause the behemoth to spawn above the train tunnel. However, taking the teddy might cause the behemoth to spawn because it is angry that somebody stole his precious teddy! When he spawns, the Behemoth may get caught up fighting Talon Company/Regulators (depending on your Karma) near the Jury Street Station. Another good tactic is to get 10 bottlecap mines, place them around the area he spwans, to the right of the tunnel and spawn him by taking his teddy, he will instantly be killed when he spawns, saving you ammo and time.

It's also possible to snipe the Behemoth from the cliffs near the entrance to Evergreen Mills. He won't be able to trace the fire back to you and will continue to shuffle around. Blackhawk is a good weapon for this job.

If you want to resurrect the Behemoth from GNR building for another fight, use ID# 1F1F9 (make sure the roof is high).

Trivia
Instead of the behemoth's head exploding when dying from a head shot, the top part of its skull will blast apart exposing its big brain. Strangely this enlarged brain does not make the behemoth any less aggressive, it may make it more intelligent but as no one has ever lived through administering an IQ exam, it remains to be determined. It's entirely possible that as DC supermutants grow in size with age that all behemoths are of considerably advanced aged, and are thus senile. Equally possible is that they are merely very cranky at being old and massive (which would give them very sore bodies constantly).

YouTube Videos
Video locations of all Super Mutant Behemoths 1mFXlMNH2BM&fmt

Specific Location 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