A bone giant, much like a Wight, is a large, strong, augmented version of its original form. Sometimes bone giants are the actual skeletons of giants, but giants are very rare. A skeleton is augmented by either extreme bone grafting, magic, or by fusing other bones together into one. By whatever means, the end result is always that their bones become thicker and stronger. Some have been reported to have legs like a great oak. Bone giants’ bones are not easily broken. Arrows shatter upon contact and most swords bounce back, vibrating.

Unlike their previously living forms, bone giants’ bones are no longer hollow. The space inside the bones is either filled with cement, more bone matter or some form of plague carrying/manufacturing material. Bone giants, out of choice of the resurrector, often have ram horns fused to their skulls. These horns can either show who owns the bone giant, the bone giant's power or the bone giant’s “rank” amongst the undead horde. The horns are also used practically as weapons. The skull of a bone giant is arguably one of the densest things in the undead army. Bone giants, unlike wights, do not have a friendly giant side. If a bone giant sees anything other than an undead on its side, it will not hesitate to smash it. Despite having no organs, bone giants still continue to attempt and devour what they kill.