Sabor, the Wanderer

When Sabor, the Wanderer or another warlock
enters the battlefield or attacks, he 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 this creature, then put the card back or put
it into your graveyard.)
His travels greatly informed the other warlocks of the
party's abilities.