Peacewalker Colossus is a rare Artifact — Vehicle card from Aether Revolt (AER), collector number 170. Current market price: $0.34 (foil $0.63), TCGplayer market prices via Scryfall.
{1}{W}: Another target Vehicle you control becomes an artifact creature until end of turn. Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)