"Well, just in the end -- I don't want to give anything away -- but I have to be a little bit aggressive in the end with a bunny," recalled Stone, who is an outspoken animal lover. "I cried my eyes out for about an hour."
"They sort of talked me through it and how it would be a gentle and okay thing but, no its very, very upsetting," Stone recounted. "Any idea of ever harming an animal in any way is crushing to me."
However, Stone explained that, in real life, no bunnies were actually harmed in the making of the film. "The bunny was totally fine," she explained.
The film was directed by the Oscar-nominated filmmaker Yorgos Lanthimos, whose divisive and controversial movies -- such as Dogtooth, The Lobster and The Killing of Sacred Deer -- are known for some of their shocking, often violent imagery.
The Favourite is set in 18th century England and tells the story of Queen Anne's (Olivia Colman) friendship with Lady Sarah (Rachel Weisz), which is challenged by the arrival of an ambitious new servant named Abigail (Stone).
As Abigail begins to charm her way into Queen Anne's trust and friendship, Lady Sarah becomes increasingly jealous, and the rivalry between the two grows deeper and more vicious.
Some scenes involved some intense physical confrontations between Stone and Weisz's characters, with both serving up and taking some hits -- which Stone said is just something that comes with the territory when shooting a movie like this.
"I think dishing is easier than taking it, but at the same time, it's all a part of the job," Stone joked.
The Favourite -- which also stars Nicholas Hoult, Taylor Swift's boyfriend Joe Alwyn and Sherlock creator and star Mark Gatiss -- comes out Nov. 23.