Colossus Hammer is a uncommon Artifact — Equipment card from The Lost Caverns of Ixalan Commander (LCC), collector number 110. Current market price: $7.56 (foil $13.57), TCGplayer market prices via Scryfall.
Equipped creature gets +10/+10 and loses flying. Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)