AG-90 (pronounced Aygee-Ninety) was a "monster droid" constructed by the scavenger mother of Dec Hansen. Because the boy had no siblings, his mother fabricated AG-90 from a collection of components; these included the head of a J9 and the body of an agromech. Functioning as Hansen's older brother, AG-90 and Hansen were raised together on the swamp-planet Ques. The droid's memory was never wiped, resulting in an unusual and erratic character. By the year 34 ABY, the pair had joined the Resistance to fight the First Order, undergoing training as pilots in J-Squadron. However, Jothan Tiaan Jerjerrod, the leader of J-Squadron, developed a disagreement with AG-90, as he thought the droid was merely a tool and required a memory wipe. During a mission to Vodran, AG-90 and Hansen were split apart following an assault by Vodran's wildlife, and the droid unexpectedly encountered a First Order stormtrooper patrol.