Jessica Rabbit in the novel, ‘Who Censored Roger Rabbit?,’ and in the early script treatments was a very different role and character than in the final film. You can see from the range of character designs that she was still a character in flux. Jessica wasn’t always a redhead. The Jessica Rabbit who appeared in the 1983 proof-of-concept tests had a lot of Katherine Hepburn. 19 images follow
The Jessica Rabbit who appeared in the 1986 RWA proof-of-concept test had other assets… lots of them.
The final design was not pinned down until after animation had started at The Forum. Although many people contributed to the final iconic design, it was really the product of Russell Hall.