Darksteel Mutation is a uncommon Enchantment — Aura card from Commander Masters (CMM), collector number 623. Current market price: $2.60 (foil $5.22), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature is an Insect artifact creature with base power and toughness 0/1 and has indestructible, and it loses all other abilities, card types, and creature types.