Mukotai Soulripper

Whenever this Vehicle attacks, you may sacrifice another artifact or creature. If you do, put a +1/+1 counter on this Vehicle and it gains menace until end of turn.
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.)

Greasefang, Okiba Boss

At the beginning of combat on your turn, return target Vehicle card from your graveyard to the battlefield. It gains haste. Return it to its owner's hand at the beginning of your next end step.