(Plot based off of the original plot for zootopia, some characters belong to disney, others were made by me. some of the plot is also based off of zistopia, which you should check out!)
Segregation between prey and predators may have ended, but the prejudice between the groups is still very strong. Prey still fear predators, so much that predators are forced to wear these "tame collars" that shock them if their emotions get to strong. No excitement, no stimulation, and most importantly, no anger. These collars prevent predators from enjoying their lives, even from having families. The only time their collars can be removed is for medical reasons.
Nick Wilde saw segregation end when he was young, but the joy was dismissed when he was forced to put on that collar, he grew up hating it, wanting to die. If only there was a way to escape it...if only...
(caution: will be much darker and more mature than the actual movie)