Faris, 37, who plays a recovering alcoholic mother in the series, told Deadline that she decided to join the show because it was "the perfect job at the perfect time."
"After I had my baby, I reprioritized my life in general. I really wanted to play characters that gave me a different kind of fulfillment. That is a difficult thing to find, especially as an actress," she explained.
The Scary Movie star went on to say that she was looking at other projects when a manila envelope with the script for Mom landed on her doorstep. After reading the script and taking a meeting with the show's creator Chuck Lorre, Faris decided to take on the role of the flawed Christy Plunkett.
"I'm so interested in playing such complicated characters and sometimes you come across a role and it feels like a Cinderella shoe," she shared. "It's so well written, that it makes your job easier and you have a gut sort-of reaction, you know instantly how you're going to say each line and that's how I felt with Christy."
The fact that the show films in L.A. also contributed to her decision, since she could stay home with husband, Chris Pratt, and the couple's 2-year-old son, Jack.
"[I] was terrified about the idea of returning to a live audience, but it's thrilling and terrifying," Faris said of her new gig. "There's no place to hide as an actor. You can't pull any of your usual tricks."
You can read Faris' entire Q&A and learn more about her upcoming joint project with Pratt and a possible future in comedy writing here.