Paar-Thur-Nax

Flying

Whenever Paar-Thur-Nax deals combat
damage to a player, you may pay {2}{u}. If you
do, exile the top card of your library face down.
You may look at that card for as long as it
remains exiled. You may play that card without paying its mana cost for as long as
Paar-Thur-Nax remains on the battlefield.