Disclaimer: Amy belongs to Joss Whedon; Hedwig belongs to J.K. Rowling. I make nothing from this, except hopefully a few giggles.
Amy was bored. She had been a rat for two years. Stuck in this stupid plastic box. It was a prison with multi-colored tubes. She was getting out.
Willow was in a hurry the last time she fed Amy, and accidentally left the cage door open. Amy waited until both Willow and Buffy had gone to patrol before making her escape. She climbed out of the cage, crawled down the desk leg, across the carpet, and up Willow's bed toward the window. She resisted the urge to urinate all over the blankets. After getting out of the dorm room, she headed to the docks. There were always ships entering and leaving Sunnydale at all times of night.
It was a long, wet trip. She overheard a few crew members mention England. Well, that was a land steeped in old magic. She would definitely find a cure to her furry problem there. It took just shy of two months to get there, and Amy jumped off the boat happily when they arrived, crawling down a thick rope.
She hid in a warehouse until nightfall, knowing that a rat would cause a panic that would likely get her killed. She scurried away from the area, eventually finding herself in a park.
"I'm free," she thought. "Finally free. Now I just need to find someone with magic who can change me back!"
Just then, a shadow fell over her. She squeaked in fright as the monster swooped down, gripping her in its talons.
Later that night, Hedwig returned to Harry's room at Number Four Privet Dr feeling quite full. That was a plump rat, even had a hint of that seafood flavor she loved best.