One strain of Porter was further refined to better use tools. Porters are fairly dexterous and could be taught to use tools but humans were better at it. It's torso adjusted and it's central legs refined into a second set of arms with it's brain considerably expanded. The result was a smarter, more dexterous creature able of truly complicated tasks and eventually able of crafting a civilization. This guy has a simple tunic with pockets and pair of shoes. Artisans live alongside domesticated Porters.