Don Nubula fought Malleo in an epic duel to the death. However, Don Nubula's castle was crumbling beneath them, and they fell. Don Nubula fell into a fountian of TOX-N, which mutated him into Iron Cerebula.
It can spit venom from it's mouth using the venom-producing stems on it's shoulders that secrete venom into it's mouth by tubes. It aslo secretes venom on the tip of it's tail (the green part). It moves round by slithering and using it's Sword-like claws.