In the German translations, Scrooge McDuck is called Dagobert Duck.
Goofy was originally called Dippy Dawg, and got his regular name through a bit of nominal evolution. The 90's series Goof Troop gave him the surname Goof. Some modern comics (c. 2005) giving him the full name Goofus D. Dawg, both canonizing his original name and establishing "Goofy" as a nickname. In the 1950s shorts that showed him in wedded "bliss" with his unnamed wife and Goofy, Junior, the mailbox read "Goofy D. Geef". He was "George Geef" for a little while. Probably "Goofy D. Geef" was some of that nominal evolution they mentioned.
Peppa Pig, and most of her friends (Danny Dog, Suzy Sheep, Zoe Zebra, Pedro Pony, Rebecca Rabbit, et cetera)
Played with in an episode of sister show Ben and Holly's Little Kingdom, which features Betty Caterpillar... who of course turns into Betty Butterfly by the end of the story.
Joey Kangaroo averts it, instead opting for a Punny Name.
Merciously mocked in one episode. Peppa, Pedro, and the rabbits are imagining a name for a new baby. All the kids imagine given names beginning with "R" except for Pedro. To his suggestion of "Sharon Rabbit" he gets looked at funny and is bluntly told that's a bad name.
Phineas and Ferb has quite a few. There's Ferb Fletcher, Doctor Doofenshmirtz, Major Monogram, Inspector Initials, Perry the Platypus, Herman the Hedgehog (apparently along with the rest of the agency, except Pinky the Chihuahua), Jeremy Johnson... plus Phineas Flynn and Carl Karl, sort of.
Seymour Skinner, Carl Carlson and Lenny Leonard from The Simpsons. Also Marvin Monroe, Gil Gunderson, Jimbo Jones, Krusty the Klown, Declan Desmond, Nabendu Nahasapeemapetilon, and Birch Barlow. Also, Fat Tony's name is once given as William Williams. (Before he was renamed Anthony D'Amico)
Also Wally Walrus, Miss Meany, Buzz Buzzard, Bessie Bear, Dapper Denver Dooley, Gabby Gator.
WordGirl's real name is Becky Botsford. Also, one of the villains she has to face in the show is Theodore "Tobey" McAllister...The Third. Since the show is an Affectionate Parody of superhero cartoons, it makes sense.