Mirelurk (Fallout 3)

Mirelurks are giant mutated horseshoe crabs living in the Capital Wasteland in 2277. Four types launched with Fallout 3, with two more added in the Point Lookout add-on.

Biology
Mirelurks descended from Chesapeake Bay horseshoe crabs. The full scientific classification of the mirelurks is kingdom: Animalia, phylum: Arthropoda, 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. (The Lone Wanderer may determine the missing classifications (both on the research terminal and in a Science dialogue check after completing the mirelurk research task for the Wasteland Survival Guide) as follows: Scylla serrata horrendus.)

Mirelurks primarily seek an aquatic habitat, particularly in and along the Potomac River (even its dried-up northern section). When not swimming, they can be found in damp and cool areas like caves, metro tunnels, and derelict facilities like the Anchorage Memorial. Despite the common condition of darkness in these areas, mirelurks are not averse to light; they are often seen during the day, particularly around the Potomac and the Anchorage War Memorial.

Gameplay attributes
All mirelurks except for kings are protected by a thick shell which is difficult to penetrate, even with powerful ballistic weapons such as the Gauss rifle. The face is unarmored but a small target, and when charging a mirelurk will lower its head to protect this area. However, the face will inevitably be exposed once the creature commences close combat. Extremities are also more vulnerable than the rest of the body, though not as much as the face. Low-level characters will find mirelurks to be among their deadliest enemies.

Mirelurks are extremely territorial, and they will attack any trespasser on sight and run it down relentlessly. They also appreciate strength in numbers, often breaking away to solicit support if there are additional mirelurks 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, however it cannot be made by the player character.

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 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 do not particularly resemble their crab-like "subjects", being more humanoid in appearance, unable to float in water, and with heads not unlike those of snapping turtles; the only commonality appears to be arms ending in pincers. They may be a separate species, living in some sort of symbiosis with the thick-shelled mirelurks.

Also unlike the other mirelurks, they have a ranged sonic projectile attack that bypasses Damage Resistance and is particularly effective at crippling the target's head. Mirelurk kings have less damage resistance than the "lower orders" of mirelurk, but require more damage to slay. They can be pickpocketed, though they don't have anything in their inventory, and reverse pickpocketing a grenade or mine reduces Karma.

Mirelurk kings appear more frequently as the Lone Wanderer reaches higher levels.

† 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 (a reflection of the effects of 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 an area of bog, marsh, or other wet, swampy ground. So the mirelurks' name is fitting, as they tend to lurk in mires.
 * Mirelurk kings are similar in appearance to the 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, giving the outward appearance of a rock (much like the mudcrabs of Bethesda's Elder Scrolls series). 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