Godrick the Grafted

Trample

When Godrick the Grafted enters the battlefield, you take the initiative.
Whenever Godrick the Grafted attacks, exile the top
card of your library. If you've completed a dungeon,
you may play that card this turn without paying its
mana cost. Otherwise, you may play that card this
turn.

I command thee, kneel! I am the lord of all that is
golden!