Ravenous Trap is a rare Instant — Trap card from Double Masters (2XM), collector number 103. Current market price: $0.36 (foil $0.65), TCGplayer market prices via Scryfall.
If an opponent had three or more cards put into their graveyard from anywhere this turn, you may pay {0} rather than pay this spell's mana cost. Exile target player's graveyard.