IG-90 was an IG-series assassin droid who worked as a bounty hunter during the Galactic Civil War. He worked with the Trandoshan bounty hunter Bossk, and was hired to join a squad of bounty hunters hired by Doctor Aphra to perform an attack on an Arquitens-class command cruiser to help Darth Vader in his research. The mission was completed when BT-1 destroyed the center of the ship. IG-90 and the rest of the bounty hunters left with more than half of their credits, or so they thought, as the rest of the credits were used by Vader and Aphra while hunting Luke Skywalker. After Aphra was captured by the Alliance to Restore the Republic during the Battle of Vrogas Vas, IG-90, along with fellow bounty hunters, Beebox, Chanath Cha, Krrsantan, C-21 Highsinger, Zuckuss, and Dengar, was hired by Vader to find and return her, either dead or alive.