Mirelurk

Mirelurks are creatures appearing in Fallout 3 and Fallout 4. They are giant, bipedal version of crabs that have been mutated by radiation.

General characteristics
Mirelurks are mutated horseshoe crabs. Based on information from The Castle in Fallout 4, Mirelurks are often ambush predators that will disguise themselves as rocks, then jump out and attack when prey gets close. They can deal massive damage and can absorb a great deal in return. Hatchlings are shown to be highly aggressive, as egg clutches will often have at least one or two hatch and proceed to attack the intruder.

Their design has changed from FO3 to FO4. They are now more crab-like, and their posture is generally crouched down to make their vulnerable faces harder to hit. Their shells also possess a mild reflective quality, as lasers are often seen ricocheting off them.

Mirelurk


A generic mirelurk, which lives close to the city's surroundings, or even the sewers.

Softshell mirelurk
A weaker version of the Mirelurk found in Fallout 4.

Mirelurk hatchling
Small, radroach-like creatures that spawn from the eggs of a Mirelurk clutch.

Mirelurk king


Male mirelurks, boss-like creatures.

Mirelurk queen
Large, powerful creatures of Fallout 4. They are capable of spawning Mirelurk Hatchlings and spraying the player with powerful acid.

Appearances
Mirelurks appear in Fallout 3 Fallout: New Vegas and in Fallout 4.