Jack Savage was the main protagonist of an early version of Zootopia.
Jack is a tall, slender rabbit with silver fur with black stripes on his head and ears. He wears a white shirt and a black business suit over it and he carries a gun.
In an early, James Bond-like concept for the film called Savage Seas, Jack Savage was to leave the city of Zootopia to visit an island in the "South Seas", under the command of his boss, a Judi Dench-like mouse. Jack would explore oceans filled with 'savage' creatures, which eventually led to Byron Howard's idea of a series of films about the rabbit spy.
When this idea was pitched to the studio, they loved the idea of the all-animal city in the first act. This was presumably the inspiration to have the whole film take place in the city.
Jack's character was however scrapped along with the film concept, his role as protagonist eventually given to another rabbit, Judy Hopps.