Mirelurk (Fallout 3)

Mirelurks are giant mutated horseshoe crabs living in the Capital Wasteland in 2277.

Biology
Mirelurks descended from Chesapeake Bay horseshoe crabs. The full scientific classification of the mirelurks is kingdom: Animalia, phylum: Arthropodia, subphylum: Crustacean/Chelicerata, class: Merostomata/Malacostraca, while order, family, and genus are left undetermined due to their mutation. The subphylum and class are disputed in an Enclave officer's field research terminal, as he believes horseshoe crabs and blue crabs both evolved into mirelurks, due to their DNA/RNA samples having markers from two different subphyla and classes. Furthermore, he and the player both fill in the missing order, family, and genus with the same answers (on the terminal, and in a Science dialogue check after completing the mirelurk portion of the Wasteland Survival Guide quest): Scylla serrata horrendus.

Mirelurks are found in damp and aquatic areas, such as the mouth of the Potomac river, in the river itself and around the dried up section of the Potomac river up north. If not in an aquatic habitat, mirelurks have been seen in dark, damp and cool areas like caves, metro tunnels, and derelict facilities like the Anchorage Memorial. However, mirelurks are not repulsed by light; they can be seen during the day, swimming in rivers and walking along the banks. This is especially true around Arefu, the Potomac and the Anchorage War Memorial.

Gameplay attributes
All mirelurks, except for mirelurk kings, are protected by a thick shell which is difficult to penetrate, even with powerful ballistic weapons such as the Gauss rifle. However, their face is unarmored and vulnerable, but the area is small and difficult to hit. When charging, mirelurks will lower their head to protect this area. However, they will swing their heads up during the attack animation, exposing their faces. The utilization of V.A.T.S. and an accurate weapon, such as a rifle, can be helpful. Their extremities are also more vulnerable than the rest of their carapace. Low level players will find mirelurks to be among their deadliest enemies.

Mirelurks are extremely territorial, and they will attack any trespasser on sight until it is dead. Even if the trespasser makes a run for it, the mirelurk will pursue them relentlessly until the trespasser is run down. Mirelurks will often leave combat to solicit support from other mirelurks that may be in the area.

Mirelurk meat, especially the soft shell variety, is highly nutritious and grants some of the highest HP replenishment of any food in the game. This is reinforced by Grandma Sparkle, as she will tell the player that mirelurk meat is "the best meat you can get out here". Both are slightly radioactive, but no more than typical food. Chefs throughout the wasteland have developed many culinary uses for mirelurk; the most prominent being the creation of mirelurk cakes. A recipe for these cakes can be found in a fridge in the Anchorage War Memorial.

Variants
The most common type of mirelurk has a whitish-gray shell, are about a head shorter than a normal human, and walk slightly slower than a human. Mirelurks fight with their claws and lack ranged attacks.

Additionally, at close range they can charge forward in a brief burst of speed for a headbutt, which also makes it impossible to target their face. However, their face is most vulnerable in the seconds after a headbutt, when their 'head' is raised.

‡ Due to their hard shells, shots on the torso only do half of the normal damage.

Mirelurk hunter
A much larger, reddish-brown colored version of mirelurk. In addition to their two main arms, hunters also have two pairs of small, segmented vestigial appendages growing out of their chest which they may attack with, but very rarely. Mirelurk hunters inhabit the Potomac River in the northern wastes and several sewers and caves near the metropolitan area of the Capital, along with a good number in the Anchorage War Memorial. Hunters are very aggressive and are more difficult to kill due to their increased Strength, speed, and health. They appear more frequently at higher levels. Their powerful pincers inflict heavy damage and can knock back low level characters easily.

‡ Due to their hard shells, shots on the torso only do half of the normal damage.

Mirelurk king


Mirelurk kings differ from other mirelurks, as they do not resemble their crab-like "subjects". They are not like crabs, but more akin to mutated snapping turtles. They appear more humanoid. They are possibly a separate species, sharing a symbiotic relationship with the crab-like mirelurks.

Mirelurk kings appear more frequently as the player gains higher levels. Mirelurk kings have a sonic projectile attack that disregards Damage Resistance and causes lots of limb damage to the subject's head, crippling it.

Mirelurk Kings have less damage resistance, which means they are easier to kill than Ordinary Mirelurks

Mirelurk kings can be pickpocketed, though they don't have anything in their inventory, and planting a grenade or mine grants bad Karma.

Unlike mirelurks and mirelurk hunters, they cannot float in water.

† Torso shots only do 2/3 of the normal damage.

‡ Instantly cripples target's head. Cannot be used if their head is crippled.

Nukalurk
A mirelurk hunter variation indigenous to the Nuka-Cola plant. They are oddly colored, having a dark blue exoskeleton stippled with glowing blue features along certain regions of their bodies. This coloration is probably due to prolonged exposure and/or consumption of the radioactive strontium isotope that was used to color Nuka-Cola Quantum before the Great War. Interestingly, Nukalurks appear in both "regular" and "hunter" versions like their mirelurk cousins, yet the difference is purely cosmetic.

Their meat is notable for a small boost in AP (from the Nuka-Cola Quantum), in addition to Radiation and Hit Points. However, only 10 nukalurks appear in the game, limiting the amount of meat available to no more than 10, since they do not respawn.

‡ Due to their hard shells, shots on the torso only do half of the normal damage.

Swamplurk
Swamplurks (designated "mirelurk" in-game) are a variation of mirelurk which inhabit the swamps of Point Lookout. They are visually identical to mirelurk hunters except for their size, their green-tinged shells due to the swampy environment and the lack of vestigial limbs on their abdomen.

‡ Due to their hard shells, shots on the torso only do half of the normal damage.

Swamplurk queen
Swamplurk queens (simply called swamplurk in-game) are a variation of the Capital Wasteland's mirelurk kings that inhabit the swamps of Point Lookout. Like the mirelurk kings, they are mutated from snapping turtles native to local rivers. They look extremely similar to kings, distinguishing traits being a mossy coloration and strangely shimmering glowing yellow eyes.

Unlike mirelurk kings, the swamplurk queen spits acid from its mouth, similar to a centaur. Although not radioactive, this acid is highly damaging.

Even with its lack of clothing, the swamplurk queen can be reverse pick pocketed with explosives. However, this results in some negative Karma.

† Torso shots only do 2/3 of the normal damage.

‡ Cannot be used if their head is crippled.

Catfish mirelurk


A humanoid, mutated catfish known as a "catfish mirelurk" also appears in The Art of Fallout 3, the art book available with the collector's edition of Fallout 3.

Related quests

 * The Wasteland Survival Guide
 * Oasis
 * Agatha's Song

Appearances
Mirelurks appear only in Fallout 3 and its add-on, Point Lookout.

Behind the scenes

 * A mire is a tract or area of wet, swampy ground, bog or marsh. So the mirelurks' name is fitting, as they tend to lurk in mires.
 * The mirelurk kings are similar in appearance to the creature from Creature from the Black Lagoon.
 * Early in the development of Fallout 3, when undetected, Mirelurks would crouch down and fold their limbs under their shell to avoid view, making predators merely view them as a rock. When anything came closer, they would slowly stand up.

Bugs

 * Mirelurks killed in water will often flip over on their fronts and twitch. This is purely a graphical glitch related to their wireframe. Sometimes they will twitch so much they fall right through the floor, or become trapped in walls and doors while constantly playing a collision noise that can alert other enemies.
 * Sometimes when mirelurks are killed on land, body parts will sink into the textures on the floor, as much as half their body, and the remaining parts will flail and bounce.

Sounds

 * Idle mirelurk
 * Mirelurk king sonic attack