Cadaverous humanoid monsters who appear to be nothing more than skin over bones
Bone Devils are cadaverous humanoid monsters who appear to be nothing more than skin over bones (hence the name). Each has a scorpion-like tail and each is usually armed with a large barbed bone hook. They are usually about 9 feet tall and weigh up to 500 pounds.
The bone devil's hook inflicts 3d4 points of damage, and may become stuck fast if the target of a successful attack fails to save vs. Paralysis. If this happens, tail attacks (see below) made by the bone devil on the trapped opponent are at a bonus of +2 on the attack roll. The bone devil can always free its weapon from a stuck victim with a single round's work.
The scorpion-like tail inflicts 2d4 points of damage on a hit, plus 1d4 points of Strength damage unless a save vs. Poison is made. Strength damage can kill a victim if the Strength score is reduced to less than 1. If not completely reduced to 0 or fewer points of Strength, a victim will begin regaining them at a rate of 1d4 points per turn after one full turn has passed. As with most infernals, a bone demon can only be damaged by magical weapons.
Basic Fantasy Field Guide Omnibus
Cruel devils resembling large skeletons covered in leathery white flesh with scorpion-like tails
Bone devils make their lair on the 5th plane of Hell. They are cruel, and enjoy torturing those weaker than themselves. They resemble large skeletons, covered in leathery white flesh, with a segmented tail like a scorpion.
Unlike most devils, bone devils prefer the frigid climate of their home plane. They have ultravision (60-ft range) which is more suited to icy climates.
Bone devils carry no treasure. They cannot be bribed with coins or gems, but they consider frozen humanoid flesh a delicacy.
OSRIC