Goliath, Prized Nephilim

Flash, haste, trample
As an additional cost to cast this card, sacrifice a creature. Goliath, Prized Nephilim costs {x} less
to cast for every creature in your graveyard.
{b}{b}, {t}: Goliath, Prized Nephilim fights target creature.
His laughter rang cold and brittle as his steel. While
still had his head, that is.