Aggron is a huge, bipedal Pokemon. It is primarily black with plates of silver-colored armor. The armor on its head has two pairs of holes with horns protruding from the foremost holes. Its forehead plating extends past its upper jaw in a small point. It has sky-blue eyes, and two nostril-like holes on the tip of its upper jaw. On the rim of its mouth are several pointed, fang-like protrusions and the nape of its neck and back have gray-silver armor sections. It has wide, blunt spikes on its shoulders, and gray-silver bands on its arms and legs. Its hands and feet each have three claws. It has a thick, long, black tail that it can swing at enemies. Mega Aggron is bulkier and more heavily plated than its previous state. The horns on its forehead are now shorter, and it has a third, wider horn on its nose. Using its horns, it is said to be able to destroy a steel tank. A spike projects downward from both its upper and lower jaw. The protrusions on its shoulders are longer and curve toward its head, and new spikes thrust from holes in its armbands. Its tail is thicker with two bands around it.