Cargo Ship

A mana rock hiding inside a Vehicle. The colorless it taps for is walled off, spendable only on artifact spells or artifact-source abilities: exactly the kind of restricted ramp that has long shown up on cards meant to fuel a dedicated artifact engine without accelerating the rest of your hand. What separates it from an unrestricted rock is that the ability lives on a body, and the body is a flier with vigilance. Crew 1 asks a trivial point of power from your other creatures, never from the ship, and once crewed the Vehicle attacks in the air without tapping. That untapped state is the whole wrinkle: because attacking never taps it, the ship can swing and still tap for its colorless the same turn (post-combat, or on the opponent's turn), so its role as an attacker never eats the tap its mana ability demands. The Vehicle rule is what balances the double duty: it reverts to a noncreature artifact once the turn is over, so the flier that raked in the air on your turn is an inert artifact when the opponent attacks, and holding the ground means crewing it again. Read as a threat, it is a soft evasive attacker that stays available for defense only at a repeated cost; read as a mana source, it is a walled-off rock that happens to fly. Wherever artifacts are the point, a small flier paying its own colorless costs does more than a rock that only sits there.