Necrotic Wound is a uncommon Instant card from Guilds of Ravnica (GRN), collector number 79. Current market price: $0.14 (foil $0.25), TCGplayer market prices via Scryfall.
Undergrowth — Target creature gets -X/-X until end of turn, where X is the number of creature cards in your graveyard. If that creature would die this turn, exile it instead.