Dreadferns Lurker

Delve (Each card you exile from your graveyard
while casting this spell pays for {1}.)
Dreadferns Lurker's power and toughness are
each equal to the number of creature cards in
all graveyard.
Dredge 4 (If you would draw a card, you may mill
four cards instead. If you do, return this card from
your graveyard to your hand.)