Eye of the deep

The eye of the deep, sometimes called a seaholder, was a water-dwelling relative of the beholder covered with reddish lobster-like chitin. An eye of the deep possessed two antennae with eyes on their ends and two arms ending in lobster-like claws; features that replaced the usual beholder eyestalks.

Description
Eyes were spherical creatures, wide that weighed. Two antenna-like eyestalks wriggled atop their heads while a large eye was located in the middle of their bodies. A pair of large arms ending in crab-like claws were located at their bottom sides, brightly colored chitinous plates armored their bodies, and their mouths were filled with razor-sharp, shark-like teeth. Hidden underneath their bodies were approximately 60–90 sticky white "feelers", which could be used to paddle through the water or cling onto rocks, although they were usually found floating silently through the water.

Behavior
Eyes of the deep were as deceptive as they were selfish, with no sense of loyalty. They would only work with other creatures if promised food or convinced that the alliance was advantageous to them in some way. They avoided others of their kind to prevent potential battles with equal foes. While not particularly intelligent compared to normal beholders, they were smart enough to employ traps and other tactical moves. They would sometimes use their illusion abilities for entertainment.

Abilities
An eye of the deep was unique in that by combining their eye rays they could achieve a special effect. When both eye rays were working in concert they could craft incredible illusions, creating moving three-dimensional images. As they grew more skilled they could create and manipulate the images without actually looking at them. They would use this ability to lure in unsuspecting survivors of shipwrecks before hitting them with their second most iconic ability. Within but a second, an eye of the deep could generate a bright white flash that stunned a target for up to a minute and blinded them for twice as long. Individually, their eye rays were capable of preventing an opponent from moving, with one being more potent than the other. Some were known to have a second eye ray that generated a wave of cold. Even in the heat of battle they could use their illusion abilities to mislead their enemies into poor tactical decisions, like creating false hope via illusions of reinforcement. While they could fool each other using illusions, eyes of the deep were immune to the flashing effect of other members of their kind. After luring in a target, they would surprise them with a flash before grasping them with their claws and ripping them apart. Their claws were both dexterous and powerful enough to cut through nets quickly with ease. Their feelers were capable of fine manipulation, and could secrete both an adhesive to grasp things, and an alcohol-like substance to counteract it. They were strong enough to lift heavy humanoids, but couldn't move while doing so.

Ecology
The eye of the deep was an extremely rare monster because it could only survive at a certain depth below the sea. If they went up to too high, their inner gases would expand inside their bodies until they exploded. Because their favorite food was surface dwellers, they would sometimes digest metallic treasures, which they would later regurgitate back in their lairs. Eyes of the deep could regenerate parts of their body given enough time with eye stalks requiring 6–11 days and other body parts needing a month, although the process could be accelerated depending on how much they ate. They did not require sleep and so could continue to create an illusion for as long as they desired. Three to six of the eye's feelers were for reproductive purposes and they would periodically deposit eggs on the ocean floor. Other eyes of the deep could fertilize these eggs two months after they were laid, and would instinctively attempt to do so. Young eyes of the deep subsisted on carrion and small fish until their powers and strength developed, splitting and then eating their plates so as to grow while they aged. They were capable of smelling blood in the water, sensing unusual currents, seeing in the dark, and telepathic communication. Their telepathy was limited to those they shared a language with.

They could also be found on the planets Karpri and H'Catha.

Society
Eyes of the deep would sometimes work with other entities like sahuagin and ixitxachitl in exchange for the bodies of land dwellers as they could not manually go to the surface. They made their homes in undersea grottoes and sunken ships (after slaying the previous inhabitants) and employed basic traps or coerced other creatures to guard their homes. Young eyes cooperated more readily with others in order to accomplish their aims.