Fog crawler Fog crawlers are creatures on the Island in 2287 . Characteristics . Biology . Fog crawlers are predatory shrimp - like creatures which live on the island surrounding Far Harbor . Fog Crawlers are a highly mutated version of the Mantis Shrimp . The different types of tail ' fans ' on different types of fog crawlers could determine their gender as crayfish carry eggs under the tails or as courtship during mating to avoid injury . The existence of the smaller legs ( swimmerets ) on the underside of the fog crawler are evidence that it is ( or was ) an aquatic crustacean . It should also be noted that the chelipeds eventually fused with the arms , creating two large dagger - like appendages ( chelipeds are the crusher - claws of a shrimp , similar to a crab ' s pincer ) . It seems that at some point the creature ' s head had evolved to become separate from the main carapace , as well as morphed into a kind of arrowhead shape for unknown reasons , possibly to be used for attacking . They seem to have eight eyes , four in a straight line on each side of the head , with the third from the left being the largest . They also seem to lack any sort of visible mouth . These creatures are remarkably tough , fast , and quite agile considering their size ; capable of withstanding multiple Gauss rifle hits with very little loss of health and a direct hit with a fat - man on higher levels . In terms of height , the average deathclaw stands just shy of a fog crawler , making fog crawlers the third largest biological entity in the game , after the mirelurk queen and behemoth . Gameplay attributes . The fog crawler ' s main attacks are slicing with its arms and jabbing with its head . It also has an attack where it jumps up and slams back into the ground , dealing massive amounts of damage to anything caught in the area of effect . This ground slam can deal damage even to targets well above the crawler ' s height level , such as human prey that believed itself safe on top of some object the crawler cannot mount . Due to their erect prosoma , fog crawlers can also strike at elevated targets with their arms . Unlike mirelurk queens or super mutant behemoths , fog crawlers lack any form of ranged attack , a shortcoming they compensate for with deceptively high speed and agility . The monstrous creatures can cover considerable distances very quickly , thus making it hard to shoot them down before they enter melee range . Their speed also makes it more difficult to escape from them . It is therefore advised to always keep an ear open for the characteristic sounds fog crawlers emit , in order to avoid running into one by accident . As mentioned above , especially the fog crawlers ' higher - level variants are extremely heavily armored , boasting resistances in the mid four - digit range coupled with an obscenely large health pool . They are easily the most resilient threat the Sole Survivor can come across and arguably more dangerous than any other giant creature in the game . Deploying the heaviest firepower available is highly recommended in any fog crawler encounter past a certain level , considering some variants can shrug off multiple direct Fat Man hits without even breaking stride . Energy weapons are the creatures ' only mentionable weakness due to their slightly lower energy resistance . Due to their armor - reinforced carapaces providing them with high damage resistance , ballistic weapons modified with armor piercing upgrades and / or the legendary effect " Penetrating " can pack a great deal of damage against them . Bear traps and legendary weapons with the Kneecapping prefix can minimize their threat considerably by crippling the legs . As fog crawlers move in a straight line toward their target , mines are extremely effective against them . Being splendid melee fighters , fog crawlers can be quite hard to defeat in a melee fight , especially because of their ground pound attack that will ignore any block attempt and stun the player character for enough time to deal additional damage with its fast slicing attacks . In a one - on - one fight against them , the use of a weapon with high base damage , energy damage modifiers and / or legendary effects such as " Furious " and " Penetrating " is recommended . Although they are most likely the Island ' s apex predators and usually attack any human , animal or creature on sight , it is not uncommon to see fog crawlers team up with yao guai or angler s to attack settlements in waves , attempting to destroy the fog condenser s . Variants . Fog crawler . While rather weak in comparison to their higher - level variants , basic fog crawlers are still a force to be reckoned with and should not be approached without proper equipment . Their high resistances require powerful weaponry to overcome ; single - shot guns with high damage output should be prioritized over rapid - fire armaments in order to have a better chance at punching through the crawler ' s heavy armor . Glowing fog crawler . A step up from the basic variant , glowing fog crawlers boast increased resistances and hit harder , especially since their strikes deal additional radiation damage . Pale fog crawler . The Pale fog crawler has a comparatively mild DR / ER , and an albino coloration . Enraged fog crawler . Boasting an obscenely high damage resistance of 4000 , enraged fog crawlers are the toughest non - legendary fog crawler subtype and the toughest enemy in the overall game . It is nearly impossible to shoot them down with any type of ballistic weapon before they come close enough to put their devastating melee attacks into play . Since they are also immune to radiation damage and poison , high - level energy weapons are the only tool that is even remotely effective against them , barring an extended Fat Man barrage . An enraged fog crawler ' s exoskeleton is tinted a comparatively bright shade of green and covered in fishing nets and boat parts . They are fairly hard to distinguish from their cousins regardless , mostly due to the Fog making it difficult to accurately discern colors at range . Enraged fog crawlers level with the player and are therefore immune to the Wasteland Whisperer perk . Considering the damage resistance progression of the other fog crawler variants ( + 50 per tier ) , the enraged fog crawler ' s DR of 4000 , compared to its ER of 350 , is probably a developmental error instead of an intentional trait . Appearances . Fog crawlers appear only in " Fallout 4 " add - on " Far Harbor " . Behind the scenes . The fog crawlers resemble the arachni - lobster creature from Stephen King ' s novella " " , which also dwells in a fog . Like the " Far Harbor " DLC , The Mist takes place in Maine .