Marsh Elemental

{t}: Put the top three cards of your library into
your graveyard. You may cast a creature card
with scavenge from your graveyard for its scavenge cost until end of turn.
Scavenge {3}{b}{b} ({3}{b}{b}, Exile this card from
your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)