Hangarback Assembler is a rare Artifact card from Alchemy: Aetherdrift (YDFT), collector number 1.
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.