Another specific application of Law of Conservation of Detail, saying that the use of non-human characters must be justified. If your character is a dog, for instance, you might do well to have the story be about his being man's best friend while making references to other dog stereotypes. If your cast is a perfectly normal family doing perfectly normal things, except they happen to all be anthropomorphic spoons or something, some audiences are going to wonder what the point is. There are reasons for a cartoon to use anthropomorphic animals instead of humans: