Foot bone

The foot bone is an item on the Odd Old Man's wishlist after the Fur 'n' Seek quest. It is dropped by Monkey Guards, cave horrors, and jungle horrors. 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.

Monkey Guards are found on Ape Atoll, which requires partial completion of Monkey Madness to reach. They are level 126 (bearded) and 128 (non-bearded) and it is recommended to use Earth spells to take advantage of their weakness. Cave horrors and jungle horrors are found on Mos'Le Harmless, which requires completion of Cabin Fever to reach. These have 2750 and 2400 health respectively, and can be easily meleed or maged.

Dropping monsters
Foot bone