Dark Bones are an easter egg item. Originally a crafting ingredient and trading item, it was functionally removed from the mod in 3.2. Its only use is in a chain of item conversions that results in the Experiment W-801.
Like most other easter egg items, Dark Bones do not appear in the creative inventory. They are also unobtainable through /give, as they are instantly deleted when obtained in this manner.
When used, the entire stack of Dark Bones will be consumed, but the output will always only be one item, so it is a waste to use more than one at a time.
- Prior to being made into an easter egg item, Dark Bones were a material from Lelyetia dropped by Exoheads (as opposed to being derived from Fleshy Bones, which are dropped by Zal Child). They were used to trade for Weapon Parts and create Exoplate Armor as well as Rockbone Armor.