Well, this was supposed to be humorous, but it quite didn't turn out that way.  Hope you enjoy anyway.
It takes place in their 5th year, after they became Animagi.

Snuffles' First Adventure

"C'mon, Sirius," James Potter moaned. "I promised Lily I'd meet her five minutes ago."

"You go ahead," Sirius said, too distracted to tease James about Lily. "I'll catch up.

He was watching a group of Slytherins who were in the same year as him and James. Sirius had just thought of an idea, but didn't think James would approve of it.

James shrugged. He was too anxious to go meet Lily to really care. As soon as he was out of sight, Sirius ducked behind an empty building, then, after first looking around to make sure no one could see him, changed into a big black dog.

Sirius Black was an Animagus. An illegal Animagus, to be exact. He would get into a lot of trouble if anyone ever found out.

One of the advantages to being an illegal Animagus was that no one would blame Sirius for the actions of one big black dog. Well, no one except than his friends, James Potter, Remus Lupin and Peter Pettigrew, who knew Sirius' secret. James and Peter were also Animagi. Remus wasn't, but he was the reason the other three had become Animagi in the first place. Remus Lupin was a werewolf.

If his friends knew what Sirius was planning, they would undoubtedly try to talk him out of it. That was why Sirius wasn't planning on telling them.

Soon the Slytherin pack came into view with Severus Snape, Sirius' enemy, leading the way.

Barking, Sirius the dog bound over and leaped up on Snape, knocking him over.

The Slytherins were all too shocked to do anything and Sirius used the few seconds to his advantage. Growling and snapping at Snape, Sirius very deliberately pissed on him before running off again.

Unfortunately Snape recovered soon than Sirius thought he would. The boy leapt to his feet and started hurling curses at the retreating dog. They all missed, but two of them rebounded and hit the dog as he turned the corner. Sirius was able to go a bit further before he collapsed and sank into a deep sleep.

~*~

Clara was skipping. She was six today. Because it was her birthday, and she was so old now, her mommy had said that she could go out 'sploring as long as she stayed where she could still see the house.

Clara saw some dandelions and decided to pick them. They would make a nice bouquet to put on the kitchen table. Mommy would be very happy.

As she leaned over to pick the flowers, she saw a big black mass in the bushes. Being six and very curious, she decided to go over and see what it was.

"A puppy!" she squealed. She threw her arms around the dog's neck. "Hey puppy. Wake up doggy."

The dog woke up and licked her face. Clara squealed again.

"Come on, doggy. Let's go home. Mommy can get us something to eat."

The dog got to his feet and Clara led the way back to her house. When she got there, she opened the door and the dog rushed past her into the house.

"Mommy! Mommy!" Clara called excitedly. "Look what followed me home! Can I keep it? Please? Please mommy? Can I keep it?"

Her mother came in. The dog, its tail wagging furiously, looked at the woman expectantly. "What's this?" she said faintly.

"She followed me home," Clara explained. "Can I keep her? Please mummy? Please? It's my birthday."

The woman crouched down. "Here, girl," she said. The dog went to her. She petted it and examined it. There wasn't any tag, but the dog was well fed and in pretty good shape. She also noticed that it was definitely not female, no matter what her daughter thought.

"Well," she said slowly.

"Please mommy? Please?" Clara begged. She looked at her mother with shining eyes.

Her mother gave in. She let go of the dog, which went back to Clara. "You can keep it. But it looks like he may belong to someone else. If they come looking for him, you'll have to give him back, okay?"

"Yeah," said Clara, who had stopped listening past the point when her mother said she could keep it.

Her mother sighed, knowing he daughter hadn't heard a word she had said. "What are you going to call it?" she asked, deciding not to press the point.

"Her name is Snuffles," Clara said, petting her new dog.

"Umm, Clara, Snuffles isn't a girl."

"Yes she is," Clara argued. "You are, aren't you, Snuffles?"

It almost seemed as if the dog was shaking its head no. At least it did to Clara's mother. Clara herself took the action another way. "See, mommy? Snuffles agrees. Snuffles is a girl."

Her mother decided not to argue the point. Clara would believe what she wanted to believe. It would do any harm.

"Come on, Snuffles," Clara said to the dog. "I'll show you my room."

~*~

It wasn't until supper back at Hogwarts that his friends noticed Sirius was missing. They had assumed he had met up with a girl, or something, and hung around Hogsmeade. It wasn't as if that had never happened before. But Sirius was always back in time for supper. He never missed a mean. So when supper came around and there was still no sign of Sirius, his friends started to get worried.

"Where is he?" James asked for the millionth time.

"We don't know," Remus said, starting to get annoyed. "You say him last. Did he say anything?"

"No," James shook his head. "He didn't say anything. Where could he be?"

They passed the Slytherins table and overheard some of them talking.

"Did you hear what happened to Severus?" a fourth year asked.

"No," her friend said. "What?"

"He was attacked by a big black dog in Hogsmeade."

"No," the girl gasped. "Really?"

"He cursed it, of course. But you'll never guess what it did to him."

James and Remus stopped listening. The exchanged a horrified glance, then, as one, took off.

"Where are you guys going?" Peter called after them. "You're going to miss supper!"

"The common room," James yelled back.

Peter shrugged. His hunger overruled his curiosity and instead of following his friends, he went to the Gryffindor table to eat supper.

"Why are we going up to the common room?" Remus asked breathlessly, following James.

"I have to get something," James replied. "Wait here," he ordered when the reached the entrance to the Gryffindor tower. Remus waited and James came back a few minutes later, carrying his Invisibility Cloak.

"Do you think Sirius is okay?" Remus asked, concerned.

"I don't know," James said honestly. He flung the cloak over Remus and himself. "Severus is a good curser. There's a good chance he's hurt."

They headed to the fourth floor. There was a good passageway that led to Hogsmeade behind a mirror on that level. It was one of the quickest and easiest ways to get there that they had found yet.

Once inside the tunnel, James took off the Invisibility Cloak. There wasn't much need for it there; no one would see them.

"So, what do we do now?" Remus asked when they reached Hogsmeade and emerged from the tunnel.

James froze. He hadn't thought that far ahead. "We can look around, I suppose," he said.

"It's getting dark out," Remus said. "And Hogsmeade is a large place. It would be like finding a needle in a haystack."

"Well, do you have any better ideas?" James asked testily.

"Where did you last see him?"

James thought for a minute. "We were pretty far away from the main part of town. C'mon, I'll show you."

The place where James and Sirius had parted ways was fairly residential. "I suppose we can go around knocking on doors," Remus said. "See if they've seen him."

"He'd better appreciate it, that's all I can say," James muttered. The things they did for Sirius . . .

The boys split up, each taking a different side of the street. They asked the people if they had seen their dog. They had no luck. Finally there was only one house left.

Remus had finished his side of the street and had been tagging along with James for the last few houses.

"Well, this is it," he said. The boys were now both very worried.

James knocked on the door. A young woman, probably only in her late twenties, early thirties, answered it. "Yes?" she said.

"Hi," James said. "We were wondering if you've seen our dog? About so high," he held his hand up to about the height Sirius was when he was a dog, "black, answers to the name of Sirius? We lost him earlier today and were wondering if you've seen or heard anything."

The woman smiled. "You're in luck," she said, motioning them to come in. "Clara," she called.

A little girl about six years old came into the room. "Yes, mommy?" she asked.

"Where's Snuffles?"

James and Remus looked at each other. "Snuffles?" James mouthed.

"He's in my room," the girl, Clara, answered.

"Bring him here," her mother told her.

The girl left, coming back with Sirius. "Is that him?" her mother asked.

Both James and Remus nodded. Sirius trotted over to his friends. The woman knelt down beside her daughter. "Clara," she said kindly. "These boys have come to take Snuffles back. They own him."

"No!" the girl cried. "She's my dog!" She ran over and flung her arms around Sirius.

"Now, Clara, I'll get you another dog."

"I don't want another dog," Clara said, tears in her eyes. "I want Snuffles."

"Ahh," James said. "That's so cute. Let's let her keep him."

Remus smacked him. "Oww!" James said, rubbing his arm. "'sides, it serves him right. We were worried sick about him, and all along he was here, pretending to be a little girl's pet."

Luckily, James had kept his voice low, so Clara and her mother hadn't heard what he said over their own argument.

"I'm sorry, Clara."

"I hate you!" Clara exclaimed. She ran off crying.

Her mother gave Remus and James an apologetic look. "I'm sorry about that. Clara really took to him."

"It's okay," Remus assured her. They headed for the door. James and Sirius took off at once, while Remus hung around for a few more minutes.

"Thanks once again," he said.

"No problem," the woman said. She laughed. "I suppose it's a good thing I decided to wait before fixing him. I thought he looked too well looked after to be a stray."

Remus choked. Fixed? "Anyway, thanks again. Bye."

"Bye." The woman waved and watched Remus join James and Sirius before closing the door.

Sirius waited until he was back in the tunnel before transforming back into his normal shape.

"Okay," James said. "What happened."

"Well," Sirius started. "I saw Snape and his gang and decided to play a trick on them."

"We heard," James said dryly.

"Do you know how dangerous that was?" Remus asked. "What were you thinking?"

"Yeah, I rather thought that's what you'd say," Sirius said. "That's why I didn't tell you. So anyway, it went fine, but Snape managed to hit me with a couple of curses. They knocked me out. When I came to, this girl was standing over me. I was a bit confused at the time and pretty sure I couldn't change back even if I wanted to, and besides, she offered me food, so I followed her home."

Remus rolled his eyes and James groaned. "You're insane, Sirius," James told him.

"Am not," he said. "I knew you guys would come and get me. And the girl reminded me of Mira." Mira was Sirius' younger sister. She was only five and Sirius would do anything for Mira. "There was no harm done. I would've left tomorrow if you hadn't come.

"We were worried about you," James yelled. "You were missing! We heard Snape cursed you! What were you thinking?"

"I think that's the whole point," Remus said. "He wasn't thinking. Were you, Snuffles."

Sirius looked embarrassed. "Yeah, girl," James added.

"Shut up," Sirius muttered. Surprisingly enough, they did.

~*~

"Where were you guys?" Peter asked when they went up the their dormitory.

"We were out rescuing Snuffles, here," James said, jerking his thumb at Sirius.

"Snuffles? Rescuing?" Peter was confused.

James sighed and sat down, preparing to tell the story. "The idiot here got on the bad end of one of Snape's curses while he was in dog form. He couldn't change back right away so he decided to let a little girl adopt him. So while we were out, worrying our asses off, he was enjoying the high life, getting fed and petted and everything."

"Why didn't you guys tell me you were going to look for him," Peter complained.

"Because you were too busy eating," James answered. He was in a bad mood and wasn't up trying to spare Peter's feelings."

"You forgot to mention the part where the girl insisted Sirius was female and called him Snuffles," Remus added mildly.

James grinned suddenly. "How could I have forgotten?"

"Okay, guys," Sirius said. "Enough with the Snuffles jokes. They're getting old."

James snorted. "No they're not," he said. "Besides, you owe us."

"I could've left at any time, thank you very much," Sirius said.

"Yeah," Remus added, "But of course the lady was about to fix you, so if it was a good thing we came when we did."

"What!" James exclaimed.

"Yeah, she told me before we left. She was about to fix Sirius."

The horrified look on Sirius' face more than made up for all the trouble they had gone through to get him back.

Epilogue

Clara was outside gardening. She had inherited the house from her mother a few years back, but she had only recently tried to fix the gardens. The inside of the house held more than enough for her to do for the first year, and all of last year Dementers had roamed the streets of Hogsmeade, keeping an eye out for the escaped convict, Sirius Black. Clara shuddered. Sirius Black was scary enough, but she preferred him to the Dementers. They were beyond awful.

But they had finally been sent back to Azkaban a few months back after attacking one of the students at Hogwarts. For that Clara was grateful. It allowed her to go outside again and tend to her gardens.

A big black dog bounded up to her. He looked very familiar. "Snuffles?" Clara said aloud. The dog just wagged its tail and panted. But it couldn't be. Snuffles would be dead by now. She had only been six when she had him.

Clara went inside and brought out some food for the dog. He looked hungry. "There you go," she said, tossing him the food. He gobbled it up, then ran off again.

"Bye Snuffles!"

The End

As always, the characters do not belong to me.  They belong to J.K. Rowling.
I hope you enjoyed, and if you did (or even if you didn't) you should review.  Reviewing is a very nice thing to do.  I like reviews.  Hey, why don't you review.  I'm hoping that if I write 'review' often enough, you'll review this story.  Maybe just to keep me from saying 'review.'  Okay, I'll shut up now.
July 30, 2000
Trinity Day