Mirelurk (Fallout 4)

Mirelurks are creatures encountered in the Commonwealth in Fallout 4.

Background
Although the games do not specifically state the origins of Mirelurks, the player can discern from their appearances that they are the products of shellfish who have been living in irradiated water for 200 years. Specifically, most Mirelurk variants have shells resembling those of horseshoe crabs. The Queen, on the other hand, has a shell that resembles that of a lobster. The Hunter appears to be a shrimp or a much smaller lobster compared to the Queen. Finally, the King is unique in that it bears no resemblance to any sort of shellfish, and may instead be a mutated frog or fish.

Characteristics
An aquatic creature that appears in Fallout 4. This specimen in particular resembles a mirelurk hunter, but also differs in several aspects, such as seen with their legs. This specimen also walks in a mixed crab/spider-like motion, which is atypical of mirelurk variants documented so far. Of course, this may be a kind of "reboot" of the mirelurk's design, in an attempt to make them look more crab-like. Mirelurks also appear to deal radiation when killed in close quarters.

Mirelurks will bury themselves in dirt or mud, with the only visual indication that they are present being the rounded backs of their shells, which resemble large, smooth rocks from a distance. VATS will be able to spot them from a distance when used.

Mirelurk hatchling
When approaching a mirelurk nest, attacking or stealing mirelurk eggs will force nearby eggs to hatch prematurely, revealing these small crab like creatures. The mirelurk queen can spawn several hatchlings to attack the player.

Mirelurk spawn
Mirelurk spawn are identical in statistics and look to Mirelurk hatchlings. A few can be found at the bottom floor of the Massachusetts State House.

Softshell mirelurk
Weak, green mirelurks encountered at low levels and can be seen mixed in with stronger mirelurks at higher levels. Two or three can be fought in the mission Pull the Plug after fixing the pipes and talking to Sully Mathis.

Mirelurk
The base type of mirelurk. Darker in appearance than the softshell variant, it is also tougher and deals more damage per hit.

Mirelurk razorclaw
A step above the Basic mirelurk but a step below the Killclaw.

Mirelurk killclaw
Powerful mirelurks, which stands by their "legendary killclaw" at Cutler Bend. These can also be encountered at higher levels in Mirelurk infested areas, like Salem.

Glowing mirelurk
An irradiated variant of the mirelurk which can be commonly encountered after the Sole Survivor levels up. A green light emits from inside of their body and they inflict radiation damage on top of the ballistic damage.

Mirelurk queen
The mirelurk queen is a new mirelurk variant. The queen is considerably larger and more dangerous than her children and inflicts more radiation on the player character. The mirelurk queen's acidic spittle rapidly damages anyone caught in it and she can spawn new hatchlings. Crippling her spouts will prevent her from using her acid attack. She benefits from the same resistance as the regular mirelurks : an incredibly thick shell but a very soft skin. It can take up to three shots from the Fat Man to kill her but half a belt from a minigun can be enough to take her down.

One occupies The Castle and is fought when the Minutemen retake it, another occupies the Murkwater construction site. Other spawn locations are Nahant Chapel, Spectacle Island, Massachusetts State House, Recon bunker Theta, west of Salem and the beach southwest of the Revere Beach station.

Mirelurk hunter
This type of mirelurk seems to have mutated from the local lobster population as evidenced by its body structure. They are significantly more resilient than regular mirelurks and gain the ability to spit acid at its enemies, as well as more powerful attacks. A few can be found at Spectacle Island, and others may spawn in the tunnels during The Big Dig.

Glowing mirelurk hunter
A irradiated variation of the mirelurk hunter, glowing mirelurk hunters deal additional radiation damage when attacking the player.

Mirelurk king
Mirelurk kings do no resemble the crab-like mirelurks, instead appearing to be heavily mutated frogs based on sounds they make.

Unlike the other mirelurks, they have a ranged sonic projectile attack that is particularly effective at crippling the target's head. Mirelurk kings have less health than glowing mirelurks, mirelurk hunters or mirelurk queens, although they are much more agile and efficient at range.

Appearances
Mirelurks appear in Fallout 4.

Behind the scenes
The mirelurk model was created by Jonah Lobe, with their Fallout 4 model bearing close similarities to the Garthim from the movie The Dark Crystal.

Bugs
Receiving acid damage from a mirelurk may cause the skin effect to remain forever. Reloading a save can possibly fix this issue.