Gary Goldman, whose credits include Total Recall and Minority Report, is suing the firm and says elements of the film are based on his work.
He claims Disney copied themes, settings, plot, characters and dialogue and the title of his Zootopia concept.
Mr Goldman also claims he pitched the idea to the studio in 2000 and 2009.
The copyright infringement case suggests Disney works in "a culture that not only accepts the unauthorised copying of others' original material, but encourages it".
