Jadelight Ranger is a rare Creature — Merfolk Scout Ranger card from Rivals of Ixalan Promos (PRIX), collector number 136s. Current market price: — (foil $1.66), TCGplayer market prices via Scryfall.
When this creature enters, it explores, then it explores again. (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. Then repeat this process.)