Son of renowned Stonecrafter Goric Kengrom, Arrak was made fun of for being the lightest build of all his brothers. From a young age, he was made to haul sacks of quarried stone to his father's workshop. He wasn't able to lift the larger stones (which drew the ire of his kinfolk initially), but he was a courageous kid, and refused to be made fun of. He would fill a small sack full of stones and would run to and from quarry to shop to make up for his light load.
Some days he would end up moving twice as many stones as his bigger brothers. His friends called him the "Stonerunner", as they would often see him fly past with a sack of stone on his back, only to rush back and do it again all day long.
Goric would regularly send Arrak to fetch the best stone from distant places, and have him rush them back for overdue projects (usually for crafting great stone weapons for the finest warriors in the land). He was by no means the strongest of his sons, but he was the hardest working.

Having now several sons to help with crafting, Arrak himself is a fine craftsman and often fashions intricate adornments and trinkets, but it's clear that is an even finer athlete. All the years spent running sacks of stone on his back have paid off, and he now plies his trade as a Runner for the Anvils.