Colossal Dreadmask is a common Artifact — Equipment card from Modern Horizons 3 (MH3), collector number 148. Current market price: $0.17 (foil $0.19), 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 +6/+6 and has trample. Equip {3}{G}{G}