Mirelurk

Mirelurk is the colloquial term for a collection of several distinct, unrelated species of mutant aquatic arthropods that inhabit the lakes, swamps, and coastal regions of the wasteland.

Common Mirelurk
The common mirelurk (Limulus polyphemus horrendus) is a mutated form of the Atlantic horseshoe crab, capable of thriving in both freshwater and saltwater environments. The common mirelurks has a thick, domed carapace and a pair of powerful pincers, and move in an upright gait, supported by four armored pedipalps.

Common mirelurks live in groups of up to two dozen individuals, and often share territory with other species of mirelurk, particularly mirelurk hunters. Rarely, a female common mirelurk will grow to immense size to become a mirelurk queen.

Mirelurk Hunter
The mirelurk hunter (Homarus americanus venatorus) is a species of mutant lobster. Like the common mirelurk, the mirelurk hunter has adapted to life in both fresh and saltwater environments. Mirelurk hunters maintain most of the characteristics of the American lobster, albeit at a vastly increased size, and have gained the ability to spray an acidic solution from ducts located beneath their mandibles.

Mirelurk hunters are solitary creatures, only interacting with others of their kind during mating season. However, mirelurk hunters sometimes share territory with common mirelurks, particularly those colonies that host a mirelurk queen.

Mirelurk Queen
In rare instances, a common mirelurk will grow to immense size and power, with some individuals estimated at over fifteen feet in height. These behemoths are called mirelurk queens (Limulus polyphemus royalis). A mirelurk queen develops acid ducts similar to those found in mirelurk hunters, as well as the ability to lay upwards of 100 eggs in a single spawning cycle.