Hangarback Assembler 

Artifact
Start your engines! When this artifact enters, conjure a card named Hangarback Walker onto the battlefield, then put a +1/+1 counter on it. Max speed — At the beginning of your end step, put a +1/+1 counter on each artifact creature and/or Vehicle you control.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyNOT LEGALvintageNOT LEGALcommanderNOT LEGAL