The Stone Brain is a rare Legendary Artifact card from The Brothers' War Promos (PBRO), collector number 247s. Current market price: — (foil $0.95), TCGplayer market prices via Scryfall.
{2}, {T}, Exile The Stone Brain: Choose a card name. Search target opponent's graveyard, hand, and library for up to four cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way. Activate only as a sorcery.