"I never got an audition [for Harry Potter]," Redmayne said in an exclusive interview with Collider. "I was sort of bereft. When I heard they were making more, a new film, I was like, 'Please can I be a part of it?'"
For Redmayne, his experience stepping into the shoes of Newt Scamander has been nothing short of "amazing."
Scamander, a magizoologist, was briefly introduced to Potter fans during Harry's time at Hogwarts as the author of the textbook of the same name.
A replica textbook was released by Rowling in 2001 as a charity for Comic Relief and served as the inspiration for the upcoming film.
Rowling wrote the script for the movie and veteran Potter director David Yates took back the director's chair for the film adaptation which introduces fans to the 1920s American wizarding world via Scamander and his magical suitcase of supernatural creatures.
"One of the most spectacular things to me about the script was, it was a thriller then it was adventure, then it was—I mean, Dan Fogler, I don't know if you've met Dan yet, but hilarious, you know," Redmayne said about Rowling's script writing. "Her stories straddle genres in the most amazing way."
"She's so passionate about her characters and she has such a sense of their whole three-dimensional world and their history," he added.