When sociolinguist Calvin Gidney watched The Lion King for the first time he was taken aback by the difference in accents of Mufasa and Scar. While the heroic Mufasa speaks with an American accent, the villainous brother has a British accent.
This made him analyse numerous cartoon shows and their characters to see if there is a pattern to this. To his surprise, he found that cartoon creators use foreign accents to represent the villains. To read more about the study and its affects on children, check-out this article by The Atlantic .