Once a Bat, Always a Bat

Fluttershy cheerfully opened the door to her cottage, delighted that the events of the night were behind her. Who knew being a vampire fruit bat for an hour could be so tiring?
"I'm home," she cooed, and her critter friends rushed to the door.
After greeting them all, she realized how famished she was. She trotted over to her kitchen and peeked into the refrigerator. As she was investigating what she had to eat, something caught her eye.
A ripe, red, juicy apple. She had gotten it fresh from Sweet Apple Acres. Apples weren't normally her favorite, but now, she couldn't take her eyes off of it.
That sure looks....good, and.....juicy, she thought to herself.
She suddenly realized what she was just thinking and shook her head. It's almost like I'm still a-
Oh no.
That can't be true, she thought to herself. When has Twilight's magic ever horribly backfired? Wait, don't answer that question.
Hoping to calm her fears, she checked herself in the mirror. Her ears, eyes, and wings were all very pony-like, not bearing any resemblance to a bat's.
Phew, she thought. That was close.
She ate her dinner and snuggled into bed, blissfully unaware that there was one feature she had forgotten to check.

Fluttershy awoke the next morning to the sound of a certain white bunny stomping the floor of her cottage. Angel held in his paws a recipe for an extremely complicated salad that she was going to have to make for him. She slowly got up, stretched, and lumbered around the kitchen to begin Angel's breakfast. Fluttershy finished the twenty-step recipe and brought over to Angel, nudging it towards him with a grin. To her suprise, Angel scampered away and cowered in the corner.
"Wait!" Fluttershy called out. "Does it really look that bad?"
She trotted over to Angel, giving him a warm smile to show that everything was okay. But for some reason, this just made him even more scared.
"What's wrong, Angel? Don't you want to eat your yummy salad?" She asked. The horrified bunny extended a shaking paw, pointing toward her mouth.
Then it all made sense. Angel's afraid of my smile. And what's in a smile?
Teeth.
No, this can't be happening, Fluttershy thought as she shot over to her mirror. Just as she feared, there was a pair of sharp, glistening fangs.
"EEEEEEEEEP!"
Horrified, Fluttershy ran from her mirror, into her bedroom, and flung herself into her closet. Oh my goodness oh my goodness oh my goodness, she thought. Twilight's spell didn't work! What should I do? Should I tell her? Oh, but what if she thinks I'm some kind of horrible monster? Or she sends me away to some laboratory to be tested? Or...or...
Dozens more terrible scenarios played through Fluttershy's mind until she came to the conclusion that she would have to keep her knew form a secret from her friends.
Okay, here's the plan, she thought to herself. I hide in here forever.
Suddenly, there was a knock at her door. "I'm not here right now," she called out, right before realizing that now whoever was at the door knew she was home.
"Ah know yer in there, Fluttershy!" It was Applejack. Fluttershy knew there was no way out of this, so she forced herself out of her closet and opened the door for the orange cowpony.
"Howdy Fluttershy!" said Applejack upon the door opening for her. "Ah was wonderin' if ya wanted to come on down to Sweet Apple Acres for the grand opening of mah vampire fruit bat sanctuary."
"Okay," she mumbled, trying not to open her mou
"Yee-haw!" Applejack exclaimed. "Yer gonna love it!"
So they went over to Sweet Apple Acres, met up with the other five, began the sanctuary, and headed back to Fluttershy's cottage so Spike could write in their diary. She did her best to hide her fangs, putting her hoof up to her mouth at times.
Once everypony had bid Fluttershy farewell and left, she was alone again to panic.
Okay, I don't think anypony saw my fangs, she thought. If they did, they didn't mention it.
Suddenly, a terrible migraine hit her. She fell to the ground, writhing in terrible pain. Her animals tried to help her, but they could only watch as her ears turned long and pointed and her eye color became a dark, deep scarlet.
The migraine finally subsided, and she looked up to see the terrified looks on the critters' faces.
"It's......okay.......friends," Fluttershy choked out. It was clear to her what had happened. Still weak from the pain, Fluttershy limped over to her mirror, her new facial features staring back at her.
"Oh my," she whispered. "I'm.....a monster."
This was too much for her. She began to sob. Sobbing turned to crying, and crying turned to outright bawling. "I......can never.......leave.......my house.......ever again." Her critters tried to comfort her, but she was inconsolable.
Suddenly, her friends burst in. They were stopping by to see how she was doing and had heard her sobs. "Fluttershy!" They shouted. "Are you okay?"
Fluttershy turned away from her friends, not wanting them to see her face.
"Darling, whatever is the matter?" Rarity asked, clearly worried about her.
"Stay back," Fluttershy whispered, not wanting to accidentally hurt her.
"Come on, Fluttershy, speak up!" Rainbow Dash shouted. "We can hardly hear you!"
"N-no, I can't tell you."
Twilight came over. "Tell us what, Fluttershy? We can't help you if you won't tell us what's wrong."
"I.......well.....I-" Fluttershy began, but was overcome by the same pain as before, this time throughout her whole body. Her friends watched as, writhing in pain, Fluttershy's fur became darker, and her cutie mark became three bats. Then, her wings shot out from behind her, and they now looked like they belonged to a bat.
"There, now you know," Fluttershy said, feeling defeated. "I'm a monster."
Her friends were staring at her, their jaws nearly touching the floor.
Then Twilight realized something. "Fluttershy, you can still talk," she said. You still have concious thought. Last night, you had the body and the brain of a vampire fruit bat. Right now, you only have the body. You're still Fluttershy, just with some.......major physical changes."
"Yea! Just like Twilight when she became a princess!" Pinkie exclaimed. "She's still our Twilight!"
"Exactly," Twilight said, impressed at Pinkie for making that connection. "And just like Zecora taught us, you should never judge a pony based on what they look like."
Everypony nodded in agreement.
"Thanks, girls," Fluttershy said. "I should've known you all would understand. But, is there anything that will turn me back permanently?"
"The spells I used yesterday were all the library had on vampire bats, but maybe Celestia knows of something. Spike, take a letter."
Spike whipped out a piece if parchment and a quill, ready to start.
Twilight cleared her throat. "Dear Princess Celestia, due to a faulty spell, my friend Fluttershy is mysteriously stuck as a batpony. I would greatly appreciate it if you would search your libraries for something that would help her. Thanks again, Twilight Sparkle."
Spike blew his green fire on the letter and sent it to the Princess.
"Does that make you feel better, Fluttershy?" Twilight asked.
"A lot," she responded. "Thanks Twilight. But what if Princess Celestia can't find a spell? What if I'm stuck like this forever?"
"Whatever happens, just know that we'll always be there for you," Twilight said. "Right, girls?"
Once again, everypony nodded.
Fluttershy was content with that. And that night, hanging on a branch outside of her cottage, she fell asleep happily, knowing that she had friends who will always love her.