Was Scrooge Donald's uncle? If HDL called him "Uncle Scrooge" wouldn't that make Scrooge and Donald brothers? (Either if by birth or marriage.)
Unless HDL called their great-uncle just "uncle."
IIRC, Donald called him Uncle as well, so I assumed the triplets were Scrooge's grandnephews.
Okay, Wikipedia says that Scrooge is Donald's maternal uncle. So apparently a Mr. Duck married a Scottish Miss McDuck and gave birth to Donald, as well as to Della Thelma Duck, the mother of Huey, Dewey, and Louie. A 1990s TV series gave the triplets' last name as Duck (and their full names as Hubert, Deuteronomy, and Louis), so either they were born out of wedlock, or their mother divorced their father and got custody, or their father died and their mother reclaimed her maiden name, or else there are just an awful lot of anatid-Americans named Duck. Anyway, since they're the sons of Scrooge's niece, i.e the grandsons of his sister, that would make them his grandnephews.
What complicates things is that Gladstone Gander, who is a male goose, is Donald's first cousin. That would mean they have a set of grandparents in common. But geese aren't the same species as ducks. Is Gladstone adopted? Also, if the common relative is a grandparent, and Scrooge is the brother of Donald's mother, that means the familial link between Gladstone and the Duck/McDuck family is the generation before Scrooge. So why is it that, according to Wikipedia, Gladstone is counted "
among the prime candidates for Scrooge McDuck's succession"? Hmm, let's see, if Gladstone is the grandson of one of Scrooge's parents, that would make him a first cousin once removed. I guess that counts as a potential heir if there's nobody closer. But wouldn't Donald and the triplets be more direct successors?
Gee, it's fun to deconstruct totally unimportant things in obsessive detail, isn't it?
As for Goofy and Pluto, the former is an anthropomorphized dog, with an upright build, no tail, and articulated hands, while the other is a conventional dog with a horizontal body, a tail, and four paws (although he can occasionally use his forepaws to grasp things). So one could assume they're different evolutionary branches -- as suggested above, like the difference between a human (great ape) and a lower primate like a monkey. Which raises the question: have we ever seen conventional, non-anthropomorphized ducks, geese, or swans in the Disneyverse/Barksverse? I'm sure we've seen other normal birds. Didn't Magica have a pet vulture? Or was that the villain from the
DuckTales movie?