Mukotai Soulripper is a rare Artifact — Vehicle card from Magic Online Promos (PRM), collector number 97953.
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.)