Optimus Maximus is a powerful mobile Autobot battle platform. It is so powerful, in fact, that some Autobot commanders are hesitant to use it, even if it could turn the tide of a battle. Even Megatron fears its power.
Optimus Maximus Commercial
Ratchet walked Bumblebee through the Autobots' motor pool, dismissing a humvee and a tank in favor of the biggest, baddest walking arsenal they had - Optimus Maximus! Manning the titan's shoulder turrets, the two Autobots rode Maximus into battle against an army of Vehicons, deploying Bulkhead from one of his arm compartments and blowing up an Energon Driller with his mighty weapons.