Jadelight Spelunker [The Lost Caverns of Ixalan Prerelease Cards]

Cost: X G When Jadelight Spelunker enters the battlefield, it explores X times. (To have it 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 that creature, then put the card back or put it into your graveyard.) The River Heralds found clues to a grand heritage below Ixalan's surface.