Carl Barks was an extremely gifted Storyteller and idea man, and he wrote nearly all of his comic book stories himself. From time to time he would receive manuscripts - or just ideas - from the professional staff writers at Western Publishing or others, but he always rewrote the manuscripts to fit his own special style and vivid imagination. The invariable result was that the stories ended up being more Barks' than anyone else's.
The only exception to that rule seems to be the early story FC0079 The Riddle of the Red Hat from 1945, which he just drew unchanged from Western's manuscript. The reason for this was that the story starred characters from the Mouse universe (Mickey and Minnie Mouse, Goofy, Clarabelle Cow and Black Pete), and that concept simply did not appeal to Barks. He faithfully completed the task but afterwards he asked to be excused from such undertakings in the future. His request was granted and he returned to his beloved Duck universe...

One of Barks' few contributors was his eldest daughter Peggy. She came up with ideas for 5 10-pagers when she was in her thirties, and her father paid her the handsome sum of 10 dollars per idea. Here they are...

WDCS198 'Knight Ball' - 1957 Donald is invited to a costume party and he dresses up as a knight in shining armour. That proves to be a wise decision!

WDCS200 'Pet Service' - 1957 Donald establishes a pet service and the nephews have to look after the customers' strange pets; an elephant, an anteater, a spider, etc.

WDCS211 'Wishing Stones' - 1958 Donald reads a book about black wishing stones on a tropical island and the nephews make fun of him for believing the story. But soon after they are all on their way...

WDCS218 'Porpoise Hunt' - 1958 Donald sees an opportunity to earn some easy money by delivering porpoises to the Seashow Aquarium. But he has to catch them first!

WDCS231 The Wax Museum - 1959 THE WAX MUSEUM Donald is the new night watchman at the Wax Museum. It would be an easy job if the figures just wouldn't move around all the time...

BONUS

No other members of Barks' family contributed ideas for his comics except his third and dearly loved wife, Garé, who came up with one gag for WDCS160 'The Camel Story' from 1954. It is the story in which the nephews are searching for a Christmas present for Donald Duck. They manage to buy a camel, no less, at a bankruptcy sale from the Bungling Bros. circus, and Donald is, of course, thoroughly shocked. He utters perplexed: Uh, Um. But didn't he cost a lot of money? Whereupon the nephews joyfully reply: Only fifty cents! If we'd had two dollars, we could have bought an elephant!