On the Astral Sea
In the ancient days of Bael Turathi, the first tiefling empire, the kruthiks were spawned in the mutagenic pits of their devilish experiments. Possessed of the traits of insects and drakes, kruthiks live in great hives, but they operate more like giant mobs. Kruthiks prefer to live in heavy terrain, burrowing into the earth in labyrinthine hive-tunnels.
Some Turathi have learned to tame and control kruthik hives, using a combination of pheromones, intoxicants, and lashings to command the elder kruthiks into bullying their smaller kin. Kruthiks make an unconventional unit to any Turathi regiment on the battlefield, but canny nobles often use them to guard the less savory entrances to their fortified homes.