Shadowed Caravel is a rare Artifact — Vehicle card from Ixalan (XLN), collector number 246. Current market price: $0.21 (foil $0.24), TCGplayer market prices via Scryfall.
Whenever a creature you control explores, put a +1/+1 counter on this Vehicle. Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)