Monstrous War-Leech Foil

Creature — Leech Horror

Kicker (You may pay an additional as you cast this spell.) As this creature enters, if it was kicked, mill four cards. (To mill a card, put the top card of your library into your graveyard.) Monstrous War-Leech's power and toughness are each equal to the greatest mana value among cards in your graveyard.