Siege Battering Ram

Trample, Siege (inflicts double damage to walls)
Crew 2 (Tap at least 2 untapped creatures you
control with total power 2 or greater: This
permanent becomes an artifact creature until end
of turn.
Additional crew you add to this vehicle once it
becomes a creature adds +1/+1 to this creature.
All creatures that crew this vehicle take 1 damage
unless they are soldiers, warriors &/or barbarians.
"At least it has a roof!"