Star Destroyer

Starship (Creatures with starship can only be blocked by other creatures with starship.)
Crew 5 (tap any number of creatures you control with total power 5 or more: This vehicle becomes an artifact creature until the end of turn.)
At the beginning of your upkeep, if you were attacked last turn create a 2/2 Artifact vehicle token named Tie Fighter with starship and crew 1 and create a 1/1 black stormtrooper creature token.