I read a few years ago in an interview with Mel Brooks, that he wrote all of the Cleavon Little lines and Richard Prior wrote all the White people jokes. You can see, in the credits, that Rich was co-writer of this project, and was going to play the main role, till contract negotioations fell apart. Also, Gene Wilder was a last minute substitute.
I've been with thousands of men, again and again, they promise the moon. They keep on coming and going and going and cumming, and always too soon. Madelene Kahn