
Socialite Holly Golighty in Truman Capote’s novella Breakfast at Tiffany’s has a cat. Or, not really. It’s more like they cohabitate. Sometimes. He comes and goes as he pleases, and she simply calls him Cat, not presuming to claim him with a name: In her eyes, he’s an independent creature, like her.
He appears in Capote’s 1958 novella as well as the 1961 film adaptation that famously features Audrey Hepburn as New York City café society girl Golightly. He’s described as a red, tiger-striped tomcat, and Holly often takes him on her fire escape with her while she plays guitar and sings.
While he merely pops in and out of the narrative to serve as a loose metaphor for Holly’s independent spirit, he ultimately plays an important role in the story’s ending.

In the final act of both the novella and the film, Holly is leaving New York for Brazil, incidentally also leaving the protagonist, who’s fallen in love with her. Defiantly trying to prove to herself that she doesn’t need sentimental attachments, she takes Cat on a cab ride and leaves him in a neighborhood far from her building.
Which she immediately regrets. She feels deeply sad moments after leaving him, realizing that she did have a bond with the cat, and she goes back to look for him in a fit of desperation.
In the novella, she never finds him. She moves to Brazil. She travels the world. She stays true to herself and her free spirit. She learns, like the protagonist does, that you can love something and let it go. The protagonist hears tell of her later in life and wonders what adventures she might be on.
In the film, she finds Cat, while also realizing she loves the protagonist back, kissing him in the rain, and deciding to (presumably) settle down with him in New York.

So, the movie and the book end on two very different notes, one of wistfulness and one of predictable romance. The book ending seems more on-brand for Holly. I can only guess why the filmmakers decided to change it, and in turn, stifle the most important part of Holly’s character—her brazen independence—but even Capote biographer Gerald Clarke agrees with me that, “The book is more authentic.”
In any case, Holly’s cat represents that we inevitably grow attached to others as we go through life, often without even realizing it. Try as you may to be self-reliant, it’s nearly impossible not to form bonds with people (and cats) as you move through the world, no matter how you live your life.
She was still hugging the cat. “Poor slob,” she said, tickling his head, “poor slob without a name. It’s a little inconvenient, his not having a name. But I haven’t any right to give him one: he’ll have to wait until he belongs to somebody. We just sort of took up one day, we don’t belong to each other: he’s an independent, and so am I. I don’t want to own anything until I know I’ve found the place where me and things belong together. I’m not quite sure where that is just yet. But I know what it’s like.” She smiled, and let the cat drop to the floor.
—Truman Capote, Breakfast at Tiffany’s