Batterskull is a mythic Artifact — Equipment card from The List (PLST), collector number NPH-130. Current market price: $5.16, 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 +4/+4 and has vigilance and lifelink. {3}: Return this Equipment to its owner's hand. Equip {5}