Mr Big is composed of two major components: the character's collection of skills, backgrounds, and such, and the mechanical construction of the Mr Big cybernetic body. The Generic Mr Big utilizes only the second part, the cybernetic body with a diminutive person inside the torso.
The Mr Big body is built off of a readily available power armor or civilian hardsuit chassis. It does not have armor plating, but it instead wrapped in a manner very similar to an autons with their stiff outer shells. The arms and legs of the suit have cybernetic limbs inside of them, anchored to the torso, giving the generic Mr Big the strength and endurance of a robot. The suit doesn't have a helmet as the pilot is concealed entirely in the torso, so the suit has an auton or other robot head in it's place.
Mr Big Gunner
The Mr Big Gunner is a paramilitary build, and has some basic armor draped over the chassis, more for cosmetic purposes. The armor carries whatever logo or insignia is used by Big Gunner's organization is. This Big has an assortment of large weapons, a handy supply of grenades, and is functionally a nine foot tall infantryman with lots of hit points, lots of weapons, and is relatively slow.
Mr Big Boomer
Similar to Big Gunner, Big Boomer has one weapon, but by god it is a big one. This isn't some squad support weapon, but something truly terrifying and impressive. A howitzer, a vehicle sized laser, an enormous flamecannon, something that deals vehicle/mecha scale damage and splash damage. This Big has one trick, but it's a blast.
Mr Big Blockbuster
Big Blockbuster is a demolition man. While proficient with big guns and power weaponry, Blockbuster carries explosives. Lots and lots of explosives. He specializes in IEDs made from naval cannon rounds, bombs made in 55 gallon drums, and has the life philosophy that there is no problem that cannot be solved with enough explosives.
Mr Big Ripper
Big Ripper specializes in melee combat, with a large melee weapon. This can be as mundane as a hardsuit sledgehammer, or as exotic as a hyperedge blade or blitzhammer. The fun is in the middle, pulling out things like chainsaw swords, melee buzzsaws, power axes, and whatever other flesh mauling hand to hand weaponry that can be thought of.
Mr Big Terror
Mr Big Terror is a monster. It is almost impossible to tell that it is a humanoid shaped machine under the carapace of bone and viscera that Big Terror has draped himself in like a macabre hermit crab. Bent on murder. Big Terror has the aura of a slasher movie killer. Tough, deliberate, and taking joy from dismantling a foe. Big Terror is a chaotic evil force of destruction suited for running with a gang or murderers and raiders of the worst stripe.
Mr Big Bling
Big Bling has clad his robotic chassis in gold composite alloy, and all of his components are cutting edge. Big Bling is a nine foot tall celebrity entourage bodyguard, and doesn't use anything as crude as missile launchers or conventional firearms. Big Bling deals exclusively in beam and energy weapons, flash and dazzle.
Mr Big Rescue
Big Rescue takes the formidable chassis of Mr Big and moves it into serving the public interest as a search and rescue responder. Big Rescue has a demeanor akin to a humanoid Optimus Prime.