湖沼蟹是变异的鳄龟，本来生活在无辐射的水域，比如米德湖中。牠們凶狠残忍，侵略性很强，会攻击任何出现在视线里的生物。通过尖叫发出一种能够致晕的声波，然后用爪子把猎物撕成碎片。They are usually found in small groups of two to three, though can occasionally be found in larger groups comprised of around five to eight. They have a high Perception, which makes them very quick to find potential prey within their immediate area.
The lakelurk king is a stronger variation of the standard lakelurk. 模型和普通湖沼蟹一样，the king has slightly glowing eyes, fins, claws, and other protrusions. 只是its chest and back颜色稍微浅一点。It can be found in the Camp Guardian caves in a large room among multiple lakelurk egg clutches. Killing it will cause the other lakelurks in the cave to frenzy and become hostile towards each other.
Cachino makes a reference to Nero "sleeping with the lakelurks," the Fallout equivalent of "sleeping with the fishes," a euphemism implying death coined in older mafia films where someone would have their feet encased in cement, then be thrown into a body of water.
Lakelurks resemble the creature "Gill-Man," depicted in the 1954 horror film Creature From The Black Lagoon.