Stoneforge Mystic is a rare Creature — Kor Artificer card from Double Masters (2XM), collector number 31. Current market price: $28.62 (foil $35.22), TCGplayer market prices via Scryfall.
When this creature enters, you may search your library for an Equipment card, reveal it, put it into your hand, then shuffle. {1}{W}, {T}: You may put an Equipment card from your hand onto the battlefield.