Ravenous Amulet is a uncommon Artifact card from Foundations (FDN), collector number 131. Current market price: $0.16 (foil $0.28), TCGplayer market prices via Scryfall.
{1}, {T}, Sacrifice a creature: Draw a card and put a soul counter on this artifact. Activate only as a sorcery. {4}, {T}, Sacrifice this artifact: Each opponent loses life equal to the number of soul counters on this artifact.