Aaron is a Purple Minion. He appeared at the end of Edith girl in the new Despicable me 2.
He is a tall two-eyed Minion with Sprout-Cut Hair.
He was turned into an evil minion. At some point later, he somehow managed to get away from Eduardo's lair.
There's a scene that Gru tried to escape from attack from an evil minion who climbed on him, then Gru threw the minion into a roof of El Macho's tower. Consequently, that evil minion may not have been sprayed by PX-41 antidote and he may be Aaron.
At the end of the movie where Gru and Lucy get married, he appeared in front of the camera, while they were taking group pictures. He got knocked out by EdithGirl.