DuckTales
When Donald Duck decides to join the US Navy, he enlists his uncle Scrooge McDuck to look after his nephews, Huey, Dewey, and Louie. Although reluctant to do so due to their hyperactivity, along with his continual pursuit of increasing his wealth and maintaining harsh business ethics, he eventually warms to them upon seeing how smart and resourceful they are, and takes them into his manor as well as a number of adventures. In addition to them, the show features frequent appearances by Gyro Gearloose, an established comic book character, as well as guest appearances by Donald in the first season – this was either a full appearance, or in a cameo scene when Scrooge and his nephews read letters he sends to them, and a few minor appearances by Scrooge's old flame, Glittering Goldie, whose character was adapted from the comic books. The show introduced new characters to the Duck universe; while some were minor including: the nanny Mrs. Beakley, whom Scrooge hires to babysit the nephews; Mrs. Beakley's granddaughter Webby; Scrooge's pilot Launchpad McQuack; Doofus Drake, an admirer of Launchpad and a close friend of the nephews; and the McDuck Manor butler, Duckworth. The second season later introduced three new additional characters as part of the show's stories: "caveduck" Bubba Duck and his pet triceratops Tootsie; and Fenton Crackshell, Scrooge's personal accountant who secretly works as a superhero named Gizmoduck.
Donald Duck in comics
In the following years both characters would become prominent members of Donald's supporting cast. In Gladstone's case, he soon started to rival his cousin in a number of personal wagers and organized contests. His incredible luck was introduced in "Race to the South Seas!", first published in 1949. This story also was the first to present Donald and Gladstone trying to win Scrooge's favor in order for one of them to become his heir. The story also explains their relationship to their rich relative: Donald is the son of Scrooge's sister and Gladstone is the son of Scrooge's sister's sister-in-law. Gladstone would also rival his cousin in a treasure hunt in "Luck of the North", first published in December, 1949. Gladstone soon became Donald's rival for Daisy's affections. The love-triangle of Donald, Daisy and Gladstone would become an ongoing theme for the following decades.