This was written for Blahblahbayern as a birthday gift! I'm a little late, and while I did change your prompt a bit (okay, maybe a lot because I couldn't resist going this route), you'll see that cat adoption and Zutara are still featured. I hope you enjoy!
An Unexpected Rescuer
Katara wakes to pain, warmth, and a slight swaying. When she blinks, it's like the world has lost half its brightness. Colours are dull and a bit blurry. This isn't right. She doesn't feel right. It's like she's been squeezed down and her whole body changed, but trying to focus makes her head ache too much. She gives up and closes her eyes.
The warmth continues to cradle her securely. Her ears twitch, picking up far too many sounds. There are voices and footsteps and the clatter of what sounds like a market. There is also soft breathing coming from somewhere above her and … a heartbeat? Is that what it is? She can feel the gentle drum against her body. Scents are sharper now as well. Herbs and a hint of spices, the sweetness of fruit starting to rot, the fish and other meats drying from racks, sweat sheening skin—pungent smells, floral smells, too many smells.
Her chest seizes up a little. This is weird. She doesn't like this, and her head hurts, and her ribs hurt, and—well, she pretty much hurts all over.
She wriggles in her anxiety. The cradling warmth tightens a little, though not too hard.
"Easy there," a low, rather familiar voice murmurs from somewhere above her. "It's okay. We're almost there."
Now her chest feels like there are bugs crawling around inside it. Or like it's about to cave in.
She dares to raise her head, catches a glimpse of a smooth jaw and green fabric. Oh no. Oh no, no, no. It all makes sense now. The "cradling warmth" is just arms holding her against a flat chest. A boy's chest. He's the source of the scent of herbs and spices as well, though now she can place the combination. He smells like tea leaves.
And he's literally carrying her like she's a baby.
She squirms even more, but his arms stay secure around her. She looks up again and this time he looks back.
Gold eyes. Big, ugly scar.
"Zuko!" Katara exclaims.
His brow creases. "Did I hurt you? I'm sorry, but you're not making it easy for me with all that wriggling."
She splutters a string of rude things at him, including a demand to be let down. But it doesn't matter what she says because he doesn't seem to understand any of it. Instead, he rubs her on the head (which, to her horror, actually feels rather nice) and laments the fact he doesn't understand meow language.
What in the actual heck?
They arrive at a rundown apartment building that looks as if as many rooms as possible have been squeezed into its thin walls. It's only once they're inside one of the pokey apartments—his?—and he sets her down gently on the floor that she realises why everything has felt so off. Her headache has stopped pulsing so much, allowing her to just stop and take a proper assessment of herself.
She has four legs.
She has a tail.
She has whiskers.
She has fur.
Zuko kneels in front of her with a frown. "Now then, little cat. Where are you hurt?"
Katara just wails. This is a nightmare.
Yes, I made her a cat. Yes, there is more to come.