Oracle Text

Legendary Artifact Creature — Robot

More Than Meets the Eye {2}{U}{R}{W} (You may cast this card converted for {2}{U}{R}{W}.) At the beginning of each end step, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.) When Optimus Prime dies, return it to the battlefield converted under its owner's control.