Fibula bone

The Fibula bone is an item on the Odd Old Man's wishlist after the Fur 'n' Seek quest. It is dropped by Turoths, which require 55 Slayer and can only be damaged by specific weapons. After the quest is completed you can no longer obtain this as a drop. The bone must be put into a pot of vinegar and boiled before giving it to the Odd Old Man.

Dropping Monsters
Fibula bone