What he looks like:
Jack was just your run of the mill, average Diamond Dog working in a small mine just outside of Canida, digging for precious gems. Well, he was more of a runt than average. His arms where much shorter than the average Dog for his size. He could dig just fine despite that. He really enjoyed his work. Not for the digging or the gems, but because he was with his friends. When a private digging company stopped by looking for recruits in exchange for rare gems he jumped at the chance in hopes that he could use the rare gems to support the mine he and his friends worked in. It sounded like the perfect plan. Jack couldn't have been more wrong...
When the private digging company, Blackbone, recruited Jack he thought that they had seen some kind of potential in him. They did. Not as a digger, but as a test subject. When he arrived at their facilities he was rendered unconscious and when he awoke he was not the same. His body was not his anymore. In place of flesh and fur there was now metal. His front paws had been turned into claws strong enough to dig through the hardest rock and sharp enough to cut the hardest of gems. His arm could become a cannon of some sort for blasting through rock. He was told that he had become the future of gem excavation and should be 'happy'. The doctor went on to tell him that gems on the front of his legs, on his forearms, and on the top of his head served as power sources for his new body and cannon. Jack didn't wait to hear anymore from the proud butcher.
He was repulsed at what he had been turned into; furious at what Blackbone had done to him. His rage led him to break free and escape; leaving a trail of destruction in his wake. He tried to go back to his friends for fear of what Blackbone might do to them, but they had already gotten to them. They were gone and their little mine stripped bare. Staying in Canida was too risky. So, he left to travel the land doing the only thing he knows: digging up gems. Deep down in his angry heart he would like nothing more than to one day shut Blackbone down for good.
He made his way to Equestria after traveling to many fantastic places and he is currently residing in the Everfree Forest where few dare to tread. There, he contends with the native wildlife to survive; readying himself for the day he and Blackbone meet again.
