Abyssal Harvester is a rare Creature — Demon Warlock card from Foundations (FDN), collector number 316. Current market price: $0.89 (foil $1.98), TCGplayer market prices via Scryfall.
{T}: Exile target creature card from a graveyard that was put there this turn. Create a token that's a copy of it, except it's a Nightmare in addition to its other types. Then exile all other Nightmare tokens you control.