This is Exilo's pony.

The idea behind this pony was to make him similar to Big Mac, keeping the very brawny, powerful build while adding something unique. The original design of the character was made an emulator on dA, but an artist on here was running a special, celshaded ponies for about $5. I figured I would snag two slots, and later gave a third slot to a friend.

The character had a couple names during his creation, the most prominent being “Ace Digger.” Eventually, his name was changed to “Black Jack,” which is his official name for now. His cutie mark is a spade, or shovel, referencing his digging. I figure the ponies would have various uses for diggers, from mining precious metals, ores, and gems, or general construction. Jack is immensely strong, able to stomp the ground and cause small tremors that can cause smaller ponies to fly into the air. Similarly, he can carry ponies on his back when they want a ride, draw carts, etc., all similar to Big Mac.

Black Jack appears in a fic that Exilo has posted on his account, “Poison Joke,” where Black Jack has a bad run in with the eponymous plant life and… things happen. The fic can be found here: http://www.furaffinity.net/view/8317544/

The picture was made by  DracosDerpyHoof and I would strongly recommend her as a skilled and thoughtful artist.
Black Jack belongs to me.