Grond, the Ravening Wolf

Trample
As long as it's your turn and you control an Army,
Grond, the Ravening Wolf is an artifact creature.
Crew 3 (Tap any number of creatures you control
with total power 3 or more: This Vehicle
becomes an artifact creature until end of turn.)
"There was a flash of searing lightning, and the doors tumbled in riven fragments to the ground."