Monstrous War-Leech

Kicker {U} (You may pay an additional {U} 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.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6ocu258x7vpb1hay4viv74.