The IG series was created to be the most intelligent assassin droids in the galaxy. However, the IG-88 model managed to gain premature conscienceness, and slaughtered the human mechanics working there. He then uploaded his conscienceness into three more robots of the same design and christened himself IG-88A and the others IG-88s B, C, and D. There was another droid in the factory that IG-88A deemed unworthy to be IG-88E, he remained the independant IG-72. The IG-88s took over the galaxy's largest droid factory on Mechis III, and secretly modified all the droids' programming. To draw attention away from their real plot, unit B became a bounty hunter. he quickly became one of the best in the galaxy. He was called to Vader's bounty for Solo. Boba Fett destroyed Unit B, and the others were destroyed soon after. But, by lucky coincedence A managed to get his mind uploaded into the second Death Star, which was destroyed in the Battle of Endor.