Lightning Rail Carriage

Passenger Exchange — {2}{u}{t}: Exchange two creatures from your hand with two creatures
crewing this vehicle. The creatures exchanged
this way enter the battlefield tapped. Activate
only if there are four or more creatures crewing Lightning Rail Carriage.
Crew 8 (Tap any number of creatures you control
with a total power of 8 or more: This Vehicle becomes
an artifact creature until end of turn.)