Angus McDuck, more commonly known as Pothole McDuck, was an anthropomorphic duck.
History
Pothole left Scotland very early in order to get rich, and settled as a steamboat captain on the Mississippi, where he was antagonized by the river pirate Blackheart Beagle and the swindling businessman Hogg. Not long after having been joined by his nephew Scrooge, Pothole retired and gave the Dilly Dollar to Scrooge. He went on writing dime novels about him entitled "Master of the Mississippi" through which he invented himself an image as one of the "far-west legends", describing himself as an equal to Davy Crockett, Dany Boone, Buffalo Bill or Calamity Jane. His growing fame later allowed him to be hired by Buffalo Bill in his traveling "western" show, that he partially financed. After a second meeting with Scrooge, he moved on again to invent comic books. His fate after that is uncertain; he was, however, deceased as of 1955, as Scrooge was entitled to his inheritence.
Behind the scenes
Pothole McDuck was first cited in the 1955 story The Great Steamboat Race, although he first actually appeared in the 1992 story The Master of the Mississippi.
Though Pothole doesn't appear in DuckTales, there is a subsitute character named Catfish McDuck who also serves, like Pothole, as Scrooge's paternal uncle gone to Mississippi to get rich and who is helped by a young Scrooge in a steamboat race.