Kalins were a monstrous insect species that resembled a cross between an ant and a spider.
On average these creatures were 10 feet in length and covered in chitinous plates that were mottled brown and yellow. They had oversized, glowing yellow eyes. Their mandibles were tremendous and their forward limbs had many sharp edges.
These creatures were rather aggressive, slightly less so than wall walkers.
Much like a spider, kalins could exude a sticky strand from their abdomens to descend from heights.
Kalin would grapple prey with their crushing mandibles and slash them with their limbs. They would ignore other creatures attacking them, focusing all attention on their grappled prey, unless severely injured.
Kalin lived a largely solitary existence, with only a few living near each other. Their mating season occurred around the fall or late summer, during which a mating pair would establish a nest and lay on average ten eggs. These eggs had a three-month incubation period, throughout which the male kalin would remain with them. After hatching, kalin were left to fend for themselves.
Kalin were a carnivorous species. They typically fed upon giant beetles, giant spiders, and tunnel worms, though on occasion they ate humanoids.
Kalin typically lived in caves or underground, where they competed with wall walkers for both prey and space.
Some cultures would attempt to domesticate kalin, though they were very unruly and difficult to handle as mounts, usually needing to be separated from other mounts. In addition, special tack and saddles were needed if a rider wanted to have them go across walls and ceilings. Those skilled in riding them were capable of fighting cooperatively with their mount.
Some primitive, cave-dwelling cultures were known to scavenge plates from dead kalin and use them to fashion crude armor, weapons, and other tools.
Monstrous Compendium Annual Volume Two, page 75.