Titan, Scrapyard Carrier

Trample, Vigilance
Titan, Scrapyard Carrier gets +0/+1 for each creature crewing it.
{3}: Untap target creature.
Crew 3, Crew 3 (Tap any number of untapped creatures you control with total power 3 or greater: This permanent becomes an artifact creature until end of turn. This must be done twice.)