A fictional mecha from the Gundam series. It first appeared in Zeta Gundam from 1985.
The PMX-003 The O is Paptimus Scirocco's personal mobile suit. Its colossal size and girth deceivingly hide its impressive maneuverability, courtesy of countless thrusters of various sizes all over the unit.
As if that wasn't enough, it loads a massively powerful beam rifle, as well as two extra arms hidden in the front skirt that can wield beam sabers of their own and overwhelm enemy units in combat.
For defense, it has a thick armor (which gave the MS its known size as said above) which can withstand both solid and beam weaponry, but not watermelon bars.