Subterranean Schooner is a rare Artifact — Vehicle card from The Lost Caverns of Ixalan (LCI), collector number 365. Current market price: $0.39 (foil $0.41), TCGplayer market prices via Scryfall.
Whenever this Vehicle attacks, target creature that crewed it this turn 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 that creature, then put the card back or put it into your graveyard.) Crew 1