Say Its Name is a common Sorcery card from Duskmourn: House of Horror (DSK), collector number 197. Current market price: $0.18 (foil $0.30), TCGplayer market prices via Scryfall.
Mill three cards. Then you may return a creature or land card from your graveyard to your hand. Exile this card and two other cards named Say Its Name from your graveyard: Search your graveyard, hand, and/or library for a card named Altanak, the Thrice-Called and put it onto the battlefield. If you search your library this way, shuffle. Activate only as a sorcery.