Gizmoduck makes his debut in the episode Frozen Assets. After a haywire security robot bars Scrooge McDuck from entering his money bin, Gyro Gearloose invents a high-tech robo armor which he names "Gizmoduck". To protect it from falling into the wrong hands, Gyro sets up the codeword "Blatherskite", an archaic word meaning nonsense which no one uses anymore... almost no one.
When Fenton hears about the suit, he conspires to borrow it but fails to don the suit initially. In frustration, he unwittingly speaks his notable mannerism "Blathering Blatherskite", to which the suit responds and dons itself upon him. Gizmoduck uses his new armor to destroy the unstable security robot.
Interference from a TV remote dismantles the suit from Fenton's body (Full Metal Duck). Funny enough, the Gizmoduck suit is dry-clean only and prone to shrinkage (New Gizmo-Kids on the Block).
Gizmoduck's development was first alluded to in The Great Dime Chase!, when Gyro Gearloose was brainstorming a means of controlling and/or becoming a robot, which he dubbed Project Blatherskite. Fenton Crackshell-Cabrera later attempted to demonstrate the suit to Launchpad and Dewey but was stopped by Gyro, who claimed that it wasn't yet ready. After Gyro and several others were taken hostage by B.U.D.D.Y., Fenton donned the suit in order to save them, though he was inexperienced in it's use. He and Launchpad succeeded in stopping B.U.D.D.Y., though in the process Launchpad and Dewey became aware that Fenton was using the suit. Fenton promised Gyro that he would keep his use of it secret in the future, while Mark Beaks became obsessed with the superhero.