Blightsteel Colossus is a mythic Artifact Creature — Phyrexian Golem card from Double Masters (2XM), collector number 357. Current market price: $70.37 (foil $77.76), TCGplayer market prices via Scryfall.
Trample, infect, indestructible If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.