Abyssal Hellkite

Flying
Abyssal Hellkite's power and toughness are each equal to the number of creature cards in your graveyard.
Whenever Abyssal Hellkite attacks, you may exile target card from defending player's graveyard. If you do, put X +1/+1 counters on Abyssal Hellkite where X is the exiled card's converted mana cost.