Not any friend of yours.
You can buy these at the Bone Market for an unreasonable amount, or call in Constable Favours to receive them at the Shuttered Palace.
See Category:Human Ribcage Gain for how to obtain this item, or click to show them.
It cannot be bought or sold at the Bazaar.
See Category:Human Ribcage for pages which require this item, or click to show them.