Resembling a terrifying cross between a scorpion and an emaciated corpse, the osyluth, or bone devil, delights in prying secrets for the mortals it tortures.
A typical bone devil stands around 9 feet tall and weighs more than 400 pounds. It resembles a desiccated cadaver with clawed hands, fearsome but useless wings, and a large tail like a scorpion's, rearing over its back in readiness to use its poison-tipped stinger.
Bone devils are the torturers and inquisitors of Hell, adhering closely to the laws of the devils and reporting any offense, to matter how minor and no matter the offender, to their masters. Bone devils are universally sadists that have elevated their craft to a fine art, and they willingly consort with diabolists seeking the secrets of Hell, knowing that they will return to their own domain brimming with even more satisfying secrets for their masters.