Cenote Scout is a uncommon Creature — Merfolk Scout card from The Lost Caverns of Ixalan (LCI), collector number 408. Current market price: $0.33 (foil $0.70), TCGplayer market prices via Scryfall.
When this creature enters, it explores. (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.)