Twilight Sparkle, Ponyville’s Unicorn Librarian, sat in her personal study with many books around her. All of them had to do with mythical creatures, from the vamponies and the fae to humans and the breezies. The creature the lavender unicorn was interested though, was the legendary werewolf.
A brutal monster, werewolves were ponies that became large, muscular beasts once a month, usually around the time Princess Luna makes a full moon. The afflicted ponies became mindless, attacking and eating family and strangers alike, only returning to their senses in the morning with their normal body and the guilt of what they did. Anypony bitten by a werewolf and survived was doomed to the same fate. The only cure was to kill and eat the heart of the one who bit you...or death.
Unfortunately this was common knowledge and none of the books Twilight had in the Golden Oaks Library had information on a particular type of werewolf she was interested in. She sighed and massaged her head with her hands.
“Didn’t find anything, huh Twilight?” The librarian looked back and smiled at the dragon behind her,
“Unfortunately not, but that’s why we are going to record the effects tonight. You ready Spike?” She asked her little brother, although he wasn’t so little anymore. Built like the more muscular members of the Equestrian Royal Guard and taller than Shining Armor, the purple and green drake was much more like a pony than other dragons, an effect of Twilight hatching him with her magic so long ago.
“Sure am Twi, just finished closing up the library.” He said as he picked up a specific journal and quill, turning to a clean page as he readied himself to write down what Twilight dictated. “You got the clothes Rarity made for you on?”
Twilight nodded and looked outside at the sky, watching the colors darken as she got up to stand in front of a large mirror. “I should be feeling it right about….now.” She said as she shivered, a tingle of odd magic making it’s way through her. “Alright. Before the transformation begins, subject will feel a wave of magic pass through their body. This signals that the transformation will begin in about 3 minutes, on an average instance. This ‘signal’ seems to function as a warning, a major difference from the known instance of Lycanthropy, which gives no warning before the change begins.” She said, Spike scribbling down all that his scientific sister said.
Yes, Twilight Sparkle was a werewolf. She was a very peculiar kind of lycanthrope, however. While variations to the known werewolf curse aren’t very rare, whatever she was had never been recorded before. Not in all the books of Equestria. After coming to terms with her curse and the probability that she would never be rid of it, she turned to science.
Tonight would be the first night she would be able to have Spike watch and record the effects of her transformation, thanks to the special outfit Twilight was wearing. It looked plain and simple, a long blue skirt with a dark purple blouse, her cutie mark on the back. What made this outfit special was that it would fit her werewolf body, as before she had to strip to prevent destroying her day clothes from how her body grew.
Speaking of, the tingling of magic returned, filling up her body. “Ooof...there it is now. Ready Spike?” Spike gave her a quick nod and began to write as she changed. First up was her fur, which grew longer and fluffier as it did yet didn’t change the color of Twilight’s coat. This was one of the many differences of her subtype, and was already described in detail in the journal of the muscular dragon. Most werewolves turned shades of black and brown with a rare white, never staying the same color.
Next was Twilight’s head changing, her ears becoming more angular as her muzzle shifted, filling with sharp canine teeth, yet not as sharp as other werewolves are supposed to have. She sneezed as her nose changed, eyes shrinking slightly as her vision improved. Her horn stayed, another major difference as werewolves lost their pony magic when they transformed, horns or wings dissapearing.
Spike was scribbling furiously to keep up as the purple lycanthrope’s tail changed, becoming more like a dog’s, wagging a bit in her excitement. Throughout all this, her transformation hadn’t hurt. In fact Twilight had come to quite enjoy changing every night, while normal curse bearers went through excruciating pain. She was very lucky.
Next were her hooves and hands, which Twilight sat in a nearby chair for. The librarian’s hooves and legs shifted, the end turning into large wolf paws while the structure shifted to work with them, ankles moving up a bit and making her taller. Her hands changed as well, not by much however. They grew small pads and such but did not change much more than that. Both her hands and her paws grew small claws, not very sharp and definitely unlike an average werewolf.
The next step was what made her curse so much more different than the others, and the reason for specialized clothes. While werewolves all grew larger during their transformation, Twilight Sparkle grew at the end of it. Not only that, but while other werewolves grew muscular, the purple wolf got...fat. Really fat.
A blush could be seen through her fluffy face fur as a rumble sounded from her belly. Then, it swelled. It grew at a good pace, not too fast nor too slow as it pushed out the front of her tucked in, button up blouse. As the gut grew chubby the wolf’s rear and breasts joined in, gaining size as she plumped up. The first nights of her curse had been filled with embarrassment and ripped clothes, but Twilight had grown to really enjoy it, as much as she hated to admit that she liked getting fat.
The werewolf continued to grow, getting bigger than her plump friend Pinkie Pie as her belly began to sag a bit from its weight. Her breasts had grown to a pleasant size and her rear and hips had widened nicely, but still she grew. One thing that Twilight and Spike learned was that Twilight would not gain any weight as a pony anymore. Instead the extra calories went to her wereform. Twilight tested this by eating nothing but sweets all day and a hard diet at night for a week. This caused her to blimp up quite a bit.
Twilight’s belly was massive now, untucking her shirt and exposing some of her fatty, fuzzy belly. It was the size of a beach ball at this point, and her breasts and rear weren't far behind. Twilight's massive, watermelon sized breasts rested on her plump gut, the orbs somehow looking perky and pleasant despite of the fat that gave them size. Meanwhile her widened hips and rear took up twice a bit of space, making Twilight needing a couch if she needed to sit and she often took up most of the space.
Her arms and legs were not spared and had thickened considerably, the limbs soft and jiggly. Twilight’s neck had grown very thick and her face had gotten adorably fat, cheeks squishing whenever she smiled. Twilight had gotten used to this however, and as she looked in the mirror she found herself...beautiful despite the extra weight.
“So...how do I look?” She asked a blushing Spike.
He gave her a wide grin. “Much better now that you have clothes that actually fit you at night.” He commented before looking at the exposed fluffy purple gut. “Well mostly anyways.”
Twilight blushed a bit more. “Yeah...hehe…” Twilight’s belly rumbled loudly before she cast a spell that banished the curse’s hunger pangs. “Goodness, good think I’ve developed that spell. I’m big enough in this form without the curse trying to make me stuff myself silly!”
That made Spike laugh. “Oh man, I wish I had a camera when I found you in the kitchen, covered in cake. You ate yourself sick!” He grinned before looking serious at his sister. “So when will you tell the others? Now that we have the clothing problem solved and know that you aren’t compelled to bite anyone, there is no reason to keep it between you, me, and Rarity anymore.”
“I know...but I’m just so nervous is all. What if something happens? What if I accidently bite someone because a bunch of ponies at once awakens a hidden instinct? What if they think I’m too dangerous to be friends with?”
Spike rolled his eyes. “Twilight you worry too much. You haven’t wanted to bite anyone over the month you’ve had this so I’m sure you won’t anytime soon. Your friends won’t leave you because you’re a werewolf and let's be honest.” Spike poked the exposed belly. “This isn’t going to spare anyone. The only thing to worry about is how much RD’s gonna laugh at your size.”
“Yeah...I suppose you’re right. I do tend to get worked up over nothing. How about we invite the girls over tomorrow, show them my new condition.”
“Sounds like a plan, Twi!” The dragon gave the werewolf the quill and journal. “Now why don’t you finish up the log while I make us dinner, you must be starving!”