Gladstone Gander is the luckiest person in the world and long standing rival and antagonizer of his cousin Donald Duck. He is nephew to Scrooge McDuck (extended family and later adoptive) and one of the possible heirs of the McDuck fortune.
Gladstone's backstory varies over the years and his appearances. The common theme is that he is a constant thorn in Donald's side as his luck looks out for him and grants him an easy ticket through life. He is almost always oblivious to how the real world works as he has never had to rely too heavily on reality to see that his needs are met. His most interesting characteristic is his luck which since his introduction in 1948 has been attributed to many different things( i.e. a painting on the family barn of the hex sign the Triple Distlefink, a lucky dollar bill Scrooge gave him as a baby, the goddess of Luck (Fortuna) being in love with him and granting him her favor, a four leaf clover his mother found, a lucky rabbit's foot, and so on and so on.) What remains the same over most interpretations of the character was that his mother Daphne was also in possession of super natural luck that she passed on to him. This usually ends in her demise while Gladstone is still a child as either a direct result of Gladstone sapping all the luck out of her or via plot devices (she and her husband Gustav died overeating at a picnic). The orphaned Gladstone was adopted by Matlida McDuck (who in some canons is married to Ludwig Von Drake making him Gladstone's possible adopted father) and raised away from the Calisota area until he reaches early adulthood and returns.
Donald and Gladstone bicker about everything. Trying to one up one another at every turn, usually ending in physical fights where one or both are usually shown worse for wear sporting black eyes and scowls. The biggest point of contention is their mutual interest in Daisy Duck, who despite being Donald's main squeeze allows Gladstone to pursue her as well.
Gladstone is also envious of how close Donald and Scrooge are and tries continually to prove himself more worthy of Scrooge's affection than Donald. This never works but Scrooge does soften on occasion. The cousins also bond over their Uncle and his penny pinching. Sometimes teaming up to try to show Scrooge that they can live a better life by not working as hard (or at all in Gladstone's case) than McDuck. This.. also never works.
In the 2017 cartoon Gladstone is more of a vagabond. Drifting through life alone wherever the winds of fortune lead him. Little is known about him other than his luck is intact and a point of much aggravation for Donald and Scrooge as it enables him to be overly indulgent, arrogant, and lazy rather than work towards any goals and stability.
Gladstone is a happy fellow typically. Quick with nicknames and quips. He's regarded as being very handsome in the comic canon getting confused for super models and famous actors on occasion. He's lazy to the point of absurdity and often claims that even the smallest tasks are “too much work” and not worth the effort (filling out a questionnaire, making wishes,etc). He has a sharp tongue and a tendency to be be condescending when challenged. His luck hinders his basic world knowledge as he gets handed everything he needs so he lacks most basic skills (i.e. he doesn't know how to 'open an egg' so he doesn't cook them). On the occasions that he does lose his luck (through magical means usually) he tends to turn over a new leaf and learn the lesson that hard work is beneficial and rewarding only to immediately revert to his easy lifestyle once his luck is returned.
Despite his childish and often off putting behavior Gladstone loves his family. He tries to help but mostly ends up insulting people. Which he tends to do quite often. Most people regard him as a pariah as his self centered sunny nature tends to grate on people's nerves. Collective groans happen when he shows up at amusement parks, silent auctions, and anywhere games of chance are played. Usually he shrugs this off but has been known to slip into depressive states when he can't shake off his family's and the public's animosity toward him.
He actually has held several jobs over the course of the comics but only briefly in any capacity. Once the acclaim or novelty wears off he quits.
There is currently one Gladstone Gander player on Duckverse:
Gladstone and Scrooge are like oil and water. Scrooge believes in hard work and obsessive dedication where Gladstone looks for the easiest route. Scrooge sees Gladstone as a project that refuses to budge and while he does try to motivate the gander to better himself or learn a trade he loses patience quickly and usually resorts to shouting at him or outright avoiding him.
Donald and Gladstone have been at odds since childhood. Little Donald would pick on and shun young Gladstone at every turn and it very much painted their relationship as adults. The cousins knock insults back and forth like professionals and try to sabotage one another to come out on top more often then not. Though there is a rivaly and a sort of hatred on Donald's end Gladstone tends to be more playful in his initial reactions to his cousin's ire. Only escalating to the same level of fury as Donald as they butt heads.