Laurie Metcalf arrived for the first day of filming Netflix’s “Big Mistakes” with something she needed to get off her chest. She doesn’t recall where she said it, but it was probably in the hair and makeup trailer sitting next to series co-creator and her co-star Dan Levy.

“We had just barely met at that point, but I told him, ‘I have extremely big shoes to fill, and I know that in my heart because I’m playing your second TV mom,’” Metcalf tells Variety.

She, of course, was referring to Levy’s previous TV mom, played by the late comedy legend Catherine O’Hara in “Schitt’s Creek.” In O’Hara’s hands, the character of Moira Rose was a larger-than-life presence in her son’s life, learning to love him more than she loved the spotlight — or at least just as much. In “Big Mistakes,” Metcalf is tasked with playing a similarly oversized onscreen role, and she wanted Levy to know she understood the weight of that responsibility.

“We never talked about comparisons or anything like that, and I think he wanted dynamics to be different,” Metcalf says. “But I wanted to be there for his character, just as much as Moira Rose was for him in ‘Schitt’s Creek.’”

As frenetic mayoral candidate Linda Morelli, Metcalf is both a blessing and a curse to her son Nicky (Levy) and daughter Morgan (Taylor Ortega). The siblings definitely don’t need the level of stress she brings, as they unintentionally descend further into a world of organized crime. Linda is brash, carries her moral superiority as a badge of honor and fiercely protects her children, whether they like it or not. She’s a force in the Morelli family, but she’s hardly the only difficult mother in Metcalf’s recent filmography.

Also on Netflix this year, the Emmy-winner tackled the role of Augusta Gein, the mother of infamous serial killer Ed Gein (Charlie Hunnam) in “Monster: The Ed Gein Story.” Augusta is a deeply religious woman who haunts her son’s psyche even before she dies — and he “resurrects” her with the exhumed body of another woman. It is perhaps the darkest role Metcalf has ever played, at least since 1997’s “Scream 2,” when she was cast as the mother of another serial killer, Billy Loomis (Skeet Ulrich), and ended up breaking bad herself.

But in “Monster,” Metcalf wasn’t interested in playing an evil mom who was cruel to her child just for the sake of it. She needed depth, something more to grab onto.

“The challenge for me was that the darkness came from their dysfunctional relationship, and knowing that her influence on him is part of the reason why his life went in a certain direction,” she says of playing Gein’s mother. “That’s a huge responsibility to accept, to know that your character is responsible for steering him into the darkness. That, and, of course, his mental disorder. The challenges can’t just be black and white. She can’t just be pure evil and he’s pure good, and she just beats him down and beats him down. So Charlie and I tried to find, in each scene, a little bit of heart in there, a little connection, and a little bit of how he did look up to his mother, no matter how she treated him.”

In choosing any role, the Tony-winning actress — who was nominated again this year for “Death of a Salesman”— is always looking for the exhilaration of being on a stage. She said both “Big Mistakes” and “Monster” gave her that opportunity.

In the case of “Monster,” Metcalf’s scenes with Hunnam are essentially a two-hander play. Their interactions are bound to the home, where he is haunted by the ghost of her influence, criticism and ill will, before and after her death. Director Max Winkler worked closely with the two actors to create a rapport that could inform their face-offs, which operate on rage and fear.

“Any scene in film or TV that has any kind of length to it, I really appreciate because that’s where you can find some traction,” Metcalf says. “That’s where you can, as an actor, get some momentum going and really lock in with your scene partners and start to find a pace. It was really just me, Charlie and Max on set. We explored a lot. Nothing was set in stone on the page, and anybody’s idea was welcome. The best idea wins, and that’s a really comforting way to work.”

Becoming Augusta Gein was a leap of faith for Metcalf, who says there were no scripts available when the role came up. “I didn’t know what to expect walking in the door,” she says.

“Big Mistakes” was a different kind of leap. Levy and co-creator Rachel Sennott’s fast-paced pilot script came with lengthy scenes and a lot of moving parts, Metcalf says.

“I think the more we rehearsed them, the more all the actors got into the groove and found our own rhythms,” she says. “We found where we could overlap, and cut each other off and cross the camera in front of each other. It was very organic, very present like theater is. I am intimidated by cameras being in the room, but less so in working that way.”

Metcalf says she immediately figured out how Linda was supposed to come barging into the lives of her children. “Dan wrote my first line of the whole series in all caps,” she says, laughing. “I knew what to do with that. It immediately got loud, and we just built from there.”

Trusting the process paid off. Metcalf’s entire “Big Mistakes” family came to see her in Broadway’s “Death of a Salesman” on opening night.

Navigating the darkness and the light of both roles brought back memories of her ”Scream 2” experience. As Debbie Salt, a fake journalist-turned-vengeful killer, Metcalf got to play in the meta sandbox of Kevin Williamson’s humor-laced horror. Nearly 30 years later, she looks back on that production as even more challenging than the dreary depths of “Monster.”

“I was very new to film back then, so the ‘Scream’ experience, for me, was a huge learning curve,” she says. “It was intense, and there were days where there wasn’t really what I would call a lightness around the set because we’re doing such heavy stuff.”

After three decades, Metcalf briefly reprised her role this year in “Scream 7.” And just like mamas Gein and Morelli, her “Scream” matriarch still has something to say.

“I find super opinionated people really funny and fun to play, because they are giving 110 percent no matter what,” she says. “Right, wrong, can’t read the room, whatever’s happening. They are giving their all.”

Just like Laurie Metcalf.