Nasus

At the beginning of combat on your turn, each
Merfolk creature you control explores. (Reveal the
top card of your library. Put that card into
your hand if it's a land. Otherwise, put a +1/+1
counter on the exploring creature, then put the card
back or put it into your graveyard.)

Whenever Nasus attacks, you may put a land card
from your hand onto the battlefield. If you don't,
draw a card.