This is (the reanimated remains of) Andy the Adventurer. Andy was very close friends with the Steve we all know and love, until that one tragic day. On that day, Steve and Andy were out mining, when all of a sudden Steve unintentionally hit Andy with his pickaxe and sent him plummeting down an enormous ravine. Andy's corpse then found its way into the mouths of some very hungry zombies, who proceeded to infect and reanimate him. This was the result.