I came across this really touching Sherlock fic last night on AO3. It's in the hearts of small things by michi_thekiller. The premise is pretty simple: John gets a new cat and names him Sherlock. However, the story itself is a bit more complex. Yes, John gets a cat and names him Sherlock, but that happens after John contemplates suicide (in the face of the original Sherlock's "death"). And the cat he finds at the shelter is Sherlock. I mean, if Sherlock became a cat then this cat would be him. Oh, and the reaction from some of the other characters is fabulous. Lestrade's is probably my favourite:
“Did you get a cat?” Greg asked him, apropos of nothing.
John looked at him suddenly, surprised, unnerved, and a bit embarrassed, as if he’d been caught thinking about schoolboys doing the can-can in lingerie, rather than his little kitty-cat at home.
“Well, it’s only just...” Greg reached over and plucked a fine black hair, maybe two inches long, off of John’s jumper. “Either you’ve got a cat, or your new girlfriend is sporting a military-style haircut.”
Ah. Obvious, snorted a familiar voice in John’s head.
“Unfortunately it’s the former,” said John. “It kind of just...happened.”
“It’s funny, I actually would not have figured you for a cat lover.”
“Me either, actually,” said John. “But he’s rather perfect for me. He’s really quite adorable.” He winced at his own last statement.
But Greg just said, “Do you have any pictures?”
John currently had 157 pictures, to be precise, but he felt no need to share that fact. Instead he pulled out his phone and began showing Greg pictures of Sherlock engaged in various activities: Sherlock sleeping, Sherlock playing, Sherlock eating, Sherlock watching the telly.
“Aww,” Greg said politely. “What’s his name?”
“Sherlock,” he finally said, a moment before the silence became really awkward, rather than only just.
“Oh,” said Greg. He took a quick sip of his beer. John held his breath, and then took another large gulp of his own drink to chase the breath down.
But Greg just said, “Let me see more pictures.”
I don't think you have to be a crazy cat person to get a kick out of this story, but it's hard to know for sure because I am a crazy cat person. *g*