ShenLong, the Rain Bringer

Flying
Whenever ShenLong deals combat damage to a player, you may pay {2}{u}. If you do, remove the
top card of your library from the game face down.
You may look at that card as long as it remains
removed from the game. You may play that card without paying its mana cost as long as ShenLong remains in play.
"Rain? No, that's a dragon!"