Neatorama has an interesting, quick-read post: the stories behind ten famous logos:
Heinz' 57 varieties
Green Giant's jolly green giant
Laughing Cow's earring-wearing bovine
The Quaker Oats man
These are the depictions of Betty Crocker over the years.
1936 Betty looks like she's standing trial for murder.
1972 Betty looks like Dracula in drag.
I'm guessing that when they created the current Betty they were trying to blur her ethnicity. I like the idea but the execution looks too much like a photograph and that ruins the romance of the brand.
1955 Betty is the only one who looks like she actually bakes cakes.
For some reason I can't explain, 1965 Betty is my favorite. How about you?