Patient Naturalist is a common Creature — Human Scout card from Outlaws of Thunder Junction (OTJ), collector number 174. Current market price: $0.13 (foil $0.22), TCGplayer market prices via Scryfall.
When this creature enters, mill three cards. Put a land card from among the milled cards into your hand. If you can't, create a Treasure token. (To mill three cards, put the top three cards of your library into your graveyard.)