Esplanade Pictures sued Disney in March, claiming its film copied the work of writer Gary L. Goldman, who had pitched his franchise idea to the animation powerhouse in 2000 and 2009.

Can anthropomorphized cartoon animals be substantially similar despite differences in species, dimension and pants-wearing? Believe it or not, that question is at the center of a copyright infringement lawsuit involving Disney's mega-hit Zootopia.

Esplanade Pictures sued Disney in March, claiming its film copied the work of Total Recall writer Gary L. Goldman, who had pitched his Zootopia franchise idea to the animation powerhouse in 2000 and 2009. In May, Disney filed a motion to dismiss, telling the court there isn't enough evidence of substantial similarity between the works for the complaint to proceed and arguing that this is the latest in "a long history of plaintiffs coming out of the woodwork after a motion picture has achieved critical and financial success to claim credit — and proceeds — where none is due."

Disney attorney Daniel Petrocelli ignored Goldman's alleged contacts with Disney executives in his motion to dismiss. This is significant because a successful copyright infringement claim requires both proving access to the allegedly infringed work and showing the works are substantially similar. In a reply to Disney's motion, Esplanade attorney Gary Gans chalks this up to a concession of access and focuses on the common elements across the works' characters, plot, mood and themes.

Gans acknowledges there are differences between the two Zootopia films, but argues that just because some of the elements aren't infringing doesn't mean the work as a whole also isn't. In Goldman's story, a live-action human animator creates a "cartoon world of animated anthropomorphic animals called 'Zootopia'" — and, while Disney's film includes no live-action elements, Esplanade claims it copies characters, dialogue, artwork, plot points and themes from the animated portion of Goldman's work. (Read the brief in full below.)

"In the face of the clear-cut allegations of copyright infringement, Disney desperately distorts the Complaint and attempts to obfuscate its wrongdoing by focusing on the parts of its movie it did not copy from Esplanade’s work," writes Gans. "The fact that differences between the works exist is simply immaterial, particularly in light of the many striking and substantial similarities that prove infringement."

Gans spends the bulk of his opposition describing the details from Goldman's Zootopia that are apparent in Disney's film, and discussing how his character Mimi the squirrel is similar to Judy Hopps, despite not being a rabbit and not wearing clothes.

"Both Zootopias involve the story of a small, cute, furry, female, prey animal, who is an outsider to “Zootopia,” he writes. "She is dismissed by more dominant animals because of her species, and strives to overcome societal prejudice. ... She becomes friends with an abrasive predator who lives in Zootopia. ... The two contrasting protagonists get together and contend with prejudice and preconceived notions of the elite, including a power structure headed by species dominant in a state of nature."

Spoiler alert — Esplanade also says Disney's Zootopia uses Goldman's twist. "Each plot involves a scheme by a third character, a small prey animal, to upend the power structure, but the scheme goes too far and fails," writes Gans.

If U.S. District Court judge Michael W. Fitzgerald agrees with Disney that the suit should be dropped, Gans has asked for leave to amend any deficiencies in the complaint or, alternatively, to remand to state court the claims relating to breach of contract, breach of confidence and violation of California Business and Professions code. A hearing is currently set for June 26.