Chuul Chuuls were large lobster - like aberration s with a hatred for surface - dwelling humanoid s . The many tentacles that surrounded their mouths were capable of causing paralysis with a single touch , thus leaving their unfortunate victim at the mercy of the chuul ' s powerful claws . Description . Chuuls have been described as " a horrible mix of crustacean , insect , and serpent " , but most closely resembled an 8 ft ( 2 . 4 m ) yellow - green lobster weighing 650 lb ( 294 . 8 kg ) with four long legs , two large claws , a strong protective exoskeleton , a fan - like tail , and a mass of paralysis - causing tentacles around its mouth . Abilities . Amphibious by nature , chuuls were actually not great swimmers , preferring to engage in combat either on land ( where they could survive indefinitely ) or very shallow water . A chuul would wait by a shoreline , while submerged or partially submerged in murky water , until it heard a suitable prey - item either within or without the water that it could perform a surprise attack upon . Strong physical combatants , chuuls fought by grabbing and piercing their target with their enormous claws . After the unfortunate victim was trapped within the strong grip of a chuul ' s pincer , it was either simply crushed or brought towards the creature ' s mouth tentacles , which grasped and exuded a paralytic secretion . Even if the victim was able to resist the paralysis at first , they would eventually succumb , if not to the paralysis itself then to the creature ' s mandibles . A chuul would normally try to always have one claw free during combat , so that it could deal with any other opponents that might try to interfere . If facing a large number of foes , it would drop a paralyzed or dead victim before moving onto the next attacker . Much like a number of other aberrant creatures , chuuls had psychic abilities . However , it was unusual for a young chuul to have access to such powers , instead they would gradually become able to exude psychic static as they aged . Older and larger creatures were able to emit a psychic moan that weakened resistance to psychic attacks and use a psychic lure to draw victims towards it . Chuuls were also able to see perfectly well in the dark , could fight even if blinded , were very alert , and had an innate immunity to poisons . Surface - dwelling chuul were able to speak Common , while those that made their lairs underground tended to speak Undercommon . Ecology . Chuuls really only had two , seemingly contradictory , motivations in life : to be left alone and to eat people . However , even if one of these wants was denied the chuul , it would normally automatically get the other ; if there was no - one to eat then it was undisturbed , if it was disturbed then there was most likely someone it could eat . Their desire for solitude meant that only a small subset of creatures were able to coexist peacefully with chuuls , as intruding on their terrain was extremely dangerous . Chuul could be found in aquatic lairs in a variety of watery habitats . Although they prefered swamps , jungle lakes , temperate marshes , and underground bodies of water , some individuals would purposely seek out sewer tunnels or coastline shipwrecks in order to provide themselves with a more accessible source of food . They were also known to use rivers , and even oceans , in order to travel to new locales . Chuuls could be found living as solitary creatures , in pairs , or in small groups of 3 - 5 , which were known as pods . A pod would purposely seek out a body of still water that was large enough to support the entire group . Some chuul , particularly older ones , would create lairs by digging up lake bottoms and building rudimentary structures from trees and stones . A chuul lair consisted of roughly circular rooms that were interconnected by tunnels made just large enough for the biggest member of the resident pod to squeeze through . One of the aforementioned rooms would always be a trophy room , as chuuls were born hoarders . After making a humanoid kill , a chuul would keep aside something from the victim as a trophy , whether shiny armor , a piece of jewelry , or even a well - crafted saddle . If the victim was not carrying anything of interest , then the chuul would settle for displaying their skull in their trophy room . The skull itself would be empty , but not due chuul consumption ; brains were poisonous to them . Chuuls either discarded the brain far away from their lair or traded it with the brain - eating mind flayers . A chuul could even be persuaded to barter with the items in their hoard , but only for captive humanoids or other things a chuul considered a " delicacy " . Despite their monstrous appearance , chuuls were actually more intelligent than they seemed , often setting traps and ambushes for their prey , although they were still far from civilized ; lacking any sort of culture , ability to make tools , or settlements . However , they did share a racial memory , which they possessed from the moment they hatched . This allowed a chuul to clearly recall events experienced by the previous generation of their race , but this became less and less vivid the further back it went . Such memories tended to carry one defining message though : hate and kill the humanoids . With such an innate hostility , chuuls would attack any such beings whenever they were able . However , this prejudice only extended to surface - dwelling intelligent humanoids such as dwarves , elves , human s , and halfling s ; chuuls would not prey upon other aberrants or subterranean creatures . In fact , chuuls had been known to work together with grimlock s , mind flayers , and troglodyte s if it allowed them to destroy and consume surface - dwellers . Chuuls tended to be rather prone to mutations , with magical experimentation , planar rifts , and polluted water affecting and altering them far more easily than other creatures , leading to gigantic and / or poisonous individuals . However , it was only under the experimentation of aberrant magic - users that such mutations reached truly terrifying proportions . Such tinkering was done with the aim of fully unlocking the chuuls ' psychic potential and thus create formidable minions that were not only physically powerful , but possessed potent mental powers as well . Variants . Older specimens that were able to reach a great size were known as chuul juggernauts , while an uchuulon ( also known as a " slime chuul " ) was a chuul implanted with a mind flayer tadpole .