Bonehoard is a rare Artifact — Equipment card from Commander 2015 (C15), collector number 245. Current market price: $0.34, TCGplayer market prices via Scryfall.
Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.) Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards. Equip {2}