Who the heck builds a robot that looks like a skunk in a Roman centurion's armour? MarsTech do, that's who.

There's a little backstory here: basically, there's this munitions/engineering corporation called MarsTech, and they create an advanced research and development facility - this sort of thing is generally referred as a "skunkworks", after Lockheed's example. So what does the robotics division build to kick off their ambitious development programme? Well, one engineer in the design meeting starts idly doodling a little guy on his notepad based on the mythological connotations of the company's name and the word "skunkworks", only for the doodle to be passed around the team and catch on as an informal mascot. One thing leads to another, and Avernus becomes the first of MarsTech Robotics's hyper-advanced 900-series engineering exercises.
Yes, it may be a tad silly for a munitions corporation to build a Roman skunk-bot, but I can't help but like the guy. And let's not forget that at the current level of world-building I've done, later units in the series include a robotic dinosaur-man and a large walking egg. Avernus was apparently setting a trend of weird designs even as he was constructed.

Oh, and don't ask him if he's equipped with chemical weapons. He hates that.