Necrogoyf (202) [Modern Horizons 3 Commander]

Necrogoyf's power is equal to the number of creature cards in all graveyards. At the beginning of each player's upkeep, that player discards a card. Madness {1}{B}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)