Lansbury plays the owner of New York's famed Tavern on the Green. Carrey plays a real estate developer who'd like to buy it and tear it down.
At first, Lansbury hesitated in taking on the role.
"They improved it, they made her much more meaningful as a participant in this little story and I found it was fun to do," Lansbury said.
In the story, Carrey's character inherits penguins from his late father and his life, you could say, goes to the birds. But that may not be a bad thing.
Even though Lansbury's character is not involved in most of the penguin antics, she plays an important part of the story.
"That's the reason, I think, they wanted me to do it because they needed that element, that very strong element that he was fighting against, that he was trying to overcome," she said. "It's only through his interaction with penguins that he shows me that he has worth, as she puts it."
Lansbury often played strong roles on film and TV. She says it's something that's "dogged" her throught her career.
"I guess it's because I am a strong woman," she said. "It bleeds through everything I do. But that doesn't mean I can't act very tender and sweet and not strong at all."
She's certainly shown that sweet side, too. Perhaps most famously as the voice of Mrs. Potts in the Disney classic, "Beauty and the Beast."
Lansbury said she'd love to bring back Jessica Fletcher, her mystery writer, crime-solving character from her long-running hit TV series, "Murder, She Wrote."
"Mr. Popper's Penguins" opens Friday.