Deep klik drone

An offshoot of the surface-dwelling kliks, the ancestors of the deep kliks retreated underground during the invasion of the Espers. Initially they managed to reconstruct their ziggurat hive-cities, but at some point they came in contact with one of the Old Gods. From this point they began to regress and devolve, becoming more insect-like, their culture stagnating and atrophying. Though they dress in the trappings of their forebears they no longer possess the capacity for metallurgy or gemcraft, and can only crudely manufacture simple goods. Their eyes are mostly blind, and can only differentiate between light and dark, while the exposed pits of their modified sinus cavity allow them to sense heat with vision-like clarity. Their carapaces have become leucistic in the perpetual darkness, and they cannot tolerate bright light or intense heat.

Deep kliks are divided by a caste system, having differing morphologies and roles in deep klik "society", such as it is. Drones are the most commonly encountered caste, being genderless, sterile workers, laborers, and soldiers. The most numerous are the kine, which are pig-sized larvae who never metamorphose into adults, and are reared for food. Weavers are somewhat spider-like with engorged abdomens and long, hyper-articulated limbs that they use to spin and weave silk, the only good the deep kliks manufacture. Princes and Princesses resemble extremely pale surface kliks, and are the only fertile members of their race. They enjoy only brief lives before they mate, whereupon the males are sacrificed by the drones on a specially-prepared altar to the Old Gods. The females then become Queens, metamorphosing into gargantuan slug-like creatures before bursting open with eggs. 

And if this should sound similar to The Rats in the Walls by H.P. Lovecraft, well...