228-910 is an anthropomorphic dog.
An uncle of 47-521's, Uncle 228-910 was one of the hundreds of Beagle Boys who swarmed Duckburg when they heard tell that their local relatives had finally taken control of Scrooge McDuck's fortune, wanting to get a piece of the pie. He arrived with "all the nephews and nieces".
Uncle 228-910 is mentioned in the 1975 comic story Scrooge For A Day. He is presumably one of the background Beagles seen later in the story, but which one is unknown.