Renee Zellweger is truly unrecognizable in The Thing About Pam.
And now, her costars are dishing about her transformation into the role. Zellweger stars as Pam Hupp in NBC's upcoming true crime series, which premieres on March 8, along with Josh Duhamel, Judy Greer, Katy Mixon and Glenn Fleshler.
The story tells the real-life story of Hupp, who is currently serving a life sentence for the 2016 murder of Louis Gumpenberger and is the main suspect in the 2011 murder of Betsy Faria.
Zellweger's transformation into the role—which included a wig, facial prosthetics and a body suit—was so drastic that sometimes, the cast didn't recognize her themselves.
"Renée is a method [actor]," Duhamel told E! News' Daily Pop. "So sometimes you couldn't tell if it was actually Renee or if it was Pam, until you hear her laugh or something."
He continued, "Renée is one of the greatest ever and it doesn't surprise me that she did what she did. She has never done a show like this...and for her to do this, I think was an event and I wanted to be a part of that."
Greer says that seeing Renee in all of the prosthetics, made the cast feel like they "had to rise to the occasion."
"She's a two-time Academy Award winner," Greer told E! "There's a reason."
And as far as the rest of the cast goes, Flesher told E! that he and Zellweger's characters just had a "great time hating each other" on set.
And an impressive transformation like Zellweger's takes time.
"It took a couple hours," Zellweger revealed to E! "We started about four and we whittled it down to about two."
Well, we may not spend four hours putting on prosthetic facial features, but we'll be spending countless hours streaming The Thing About Pam when it premieres on NBC.
E! and NBC are both part of the NBCUniversal family.