Restless Quirion

Whenever a land enters the battlefield under your control, if Restless Quirion is untapped,
you may tap and exert it. If you do, explore.
(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. An exerted creature won't untap during your next untap step.)