It looks like one of the biggest, baddest SUVs in production, the Mercedes-Benz G-Class, is about to get a whole lot tougher with the arrival of a new 4x4 Squared variant.

Offered on the previous-generation G-Class in G550 guise, the 4x4 Squared option saw the iconic SUV fitted with some serious off-road gear, including portal axles that lent it its now-famous stance. The setup was derived from a 6x6 version of the G-Class originally developed for military use and offered in civilian guise for a limited time.

Our spy shots show a current-generation G550 with the same fender flares and portal axles as the previous G550 4x4 Squared. There's also a custom roof rack that's likely fitted with ballast to raise the vehicle's center of gravity, which engineers often use during testing of stability systems designed to prevent rollovers.

2017 Mercedes-Benz G550 4x4² (European spec)

2017 Mercedes-Benz G550 4x4² (European spec)

In the case of the previous G550 4x4 Squared, the ride height was over 17 inches and it looks like the same will be true for the new generation. The previous G550 4x4 Squared also came with permanent all-wheel drive, a reduction transfer case, three differential locks, and of course the portal axles. The latter is what contributed to the raised height: unlike conventional axles, portal axles don't have the wheels mounted at the axle but lower via individual portal transmissions.

Mercedes hasn't even said it's working on a new G550 4x4 Squared. Should production happen, there's a good chance Mercedes-AMG will offer its own version based on the G63 this time around.

You'd best start saving if you're interested in parking a new G550 4x4 Squared on your driveway. The last one cost a steep $225,925 and we suspect any new one will cost even more.