Gladstone Gander is the son of Daphne and Goosetave Gander. Gladstone first appeared in the story "Wintertime Wager" in Walt Disney's Comics and Stories #88 (January, 1948). Gladstone is a lazy and infuriatingly lucky goose who never fails to upset his first cousin Donald Duck. Gladstone's luck defies probability and provides him with anything he desires, with hardly the need of effort. As Disney comics writer Don Rosa has commented on the character: "Gladstone is unwilling to make the slightest effort to gain something that his luck cannot give him, and, when things go wrong, he resigns immediately, certain that around the next corner a wallet, dropped by a passer-by, will be waiting for him". For all his luck Gladstone has no achievements to be proud of and no true ambitions, as he is incapable of long-term planning. All of this is in stark contrast to his relative Scrooge McDuck, who is also capable of taking advantage of opportunities but works hard to create situations favorable for him, is strongly motivated by his ambitions and takes pride in forming his fortune by his own efforts.
He is a rival of Donald for the love of Donald's girlfriend Daisy Duck. Gladstone is also considered among the prime candidates for Scrooge McDuck's succession. For all of these reasons, he and Donald have formed an intense rivalry with each other.
Gladstone Gander appears at the new Ducktales Comics at the 1st as Agent X who is hypnotized by Cinnamon so as to reveal to John D. Rockerduck and the villains where,when and which artifacts Scrooge McDuck will return to their original locations. Rockerduck also wants Gladstone so he can have his Luck on his side and with it win the bet which made with Scrooge at the 1st issue of Ducktales. Gastone is well known about his unpredictable and unmaginable luck, so John D. Rockerduck is more than that he will win the bet. He is revealed to be Agent X at the story where at the end almost of the issue Cinnamons tells him that his job hasn't over yet then hypnotizes him and commands him to go with Uncle Scrooge and return the other artifacts and to put his luck so Scrooge may not succeed in returning the artifacts in time.