So it's no surprise she looks -- and sounds -- totally comfortable in a new spread for Esquire, in which she is in turns bouncing around her Beverly Hills home via Skype and posing topless for photographer James White.
She introduces Cinnamon, her tiny dog -- with a big penis that Rossum can't help but mention -- and her cat, Fiona G. Kitty, who was a stray and a Chicago veterinarian convinced her had cancer.
"I hate cats," she explained. "But this cancer cat made me feel bad, so I was like, Okay, I’ll take her back to L. A. and give her her last six months of pain-free life."
But upon taking the cat to Los Angeles, another vet set the record straight.
"I said, Yeah, but too bad about the cancer. And he said, What cancer? And I’m like, You know, the lump on her stomach. And he’s like, You mean the hernia? I can take that out when I neuter her. She’s gonna live twenty-five years! And I was like, You [expletive] cat with your lying cancer sob story."
Still, it was another brush with death that brings out Rossum's serious side.
"It’s amazing how things can be put into perspective for you so easily," she said. "Last weekend, I was pulling out of my house, and I saw a body in the road and blood everywhere. This guy had been hit by a car."
"I called 911 and stayed with him," she recalled. "You see how lucky you are to just be alive. All the Hollywood [expletive] and accolades and money really doesn’t matter. It just gives you a slightly nicer house and slightly nicer food and slightly shinier hair."
Celebrity Couples of 2014 [PHOTOS]