I find it interesting that the original voice of Porky Pig, Joe Dougherty, really did stutter. Because he couldn’t control it, recording sessions would run too long and become too expensive, so he was replaced by Mel Blanc. Blanc kept the stutter, but used it more for comic effect. Stuttering comedians were apparently a thing at the time, and Blanc had done a similar voice on the radio. Part of the joke in Blanc’s version of Porky was that he’d substitute words when he couldn’t say something, sometimes using ones that were actually harder to say. Other character voices are also based on such impediments, like Elmer Fudd’s inability to pronounce the letters R and L. In his case, the voice came with a redesign in the character to make him look more childish, and the problem is a common one for young children.
I do have to wonder if cartoon characters whose voices include speech impediments are ever considered controversial. I’ve never thought much of it myself, but what do I know?
In addition to the speech problems, other characters have voices based on specific celebrities, or on earlier characters, like how many of Foghorn Leghorn’s catchphrases were taken from the Southern Senator Claghorn on Fred Allen’s radio show.
Still others simply used accents or dialects. It’s generally agreed now that the old minstrel-show black dialect is offensive, largely because it was connected to a history of racism. That said, I remember Beth telling me that she heard in one of her classes about how nobody seems to think anything of Apu on The Simpsons, another ethnic stereotype voiced by a white guy. Part of it might be that Apu is actually a pretty well-rounded character, quite intelligent and hard-working compared to most of the cast, but maybe not.
In addition to potential controversy, I find it interesting to look at how many cartoon characters are defined by their voices. Some of them were really a voice before they were anything else, like how Donald Duck came into being when Walt Disney heard Clarence Nash’s duck voice. For a lot of the classic characters, the voice is important, but it doesn’t totally define them. That seems to be more the case in the Hanna-Barbera television cartoons, where the animation and stories are minimal, so someone like Yogi Bear, Huckleberry Hound, or Snagglepuss largely IS his voice.