The Effects of Obesity on the Pony Body

by Skorpion

Rating: mature
Tags: Moondancer, Twilight Sparkle, Anthro, My Little Pony: Friendship is Magic
Length: 3905

Twilight can transport herself into any book at will. Moondancer has a plan. Slob fetish happens.

Twilight just wanted to get Moondancer's attention. It seemed like the perfect plan; Just teleport into her book, and if Moondancer ever wanted to study in peace again, she'd have to hear her out. Unfortunately for her, Moondancer doesn't appreciate interruptions.

Weight gain, slob, body transformation, mind alternation, non-con.

Published 2017-03-02 12:00:01 UTC
Last updated 2017-03-07 04:58:38 UTC

Original version

Author's Note

Contains everything in the description. Sweat, farting, belching, the works.

With help from ShadowofDreams

Original version

"Did... Did you just teleport into my book?" Moondancer said, rubbing her eyes.

"Yep! It's a special studying technique called the Haycartes' Method. Princess Celestia taught it to me, and if you'll just let me, I can teach it to you too!"

Moondancer stared at Twilight. The alicorn had become nothing more than a cartoonish illustration, albeit one that could move and talk. With a spell like that, Moondancer knew she would never have a moment's peace. Twilight could go into any book and bother her until she submitted, at least to a conversation. She'd follow from page to page, her annoying voice commenting on every sentence, every fact, every-

That's when Moondancer had an idea.

"Twilight," She asked, "Do you know what book this is?"

The sketchy alicorn glanced down at the caption just beneath her hooves. "The average pony weighs around 60 kilograms... Is this a diet book?"

"Yep. And if you'd take a look at the chapter title..."

"Effects of... Obesity... On the equine... Body..?" She read aloud, "What's that got to do with- Woah!"

Twilight yelped as the page suddenly flipped, sending her stumbling head over heels onto the next page, where she landed flat on her back in an illustration box. She got up and dusted herself off, glaring angrily at Moondancer. "You could've at least warned me!"

"Whoops, sorry!" Moondancer said sarcastically, "I was just so excited to read this next page!"

"High calorie intake... Combined with lack of exercise... Causes weight gain..." As Twilight read, her stomach began to grumble. "Moondancer, what's-" She started, before wincing as a strange feeling took hold in her belly. "Woah!" She gasped, her belly suddenly surging forward. Her flat belly filled up like a water balloon, hanging over her waist. Her shirt became untucked, revealing the lower quarter of her gut for anypony to see. Twilight stared down at her chubby frame, then looked up at the giant pony above her. Moondancer reached down and poked her sketched belly, causing it to jiggle.

"Moondancer, this is childish."

"What's that, Twilight?" Moondancer chuckled "You want me to turn the page?"

Twilight's eyes opened wide. "No, wait a second-"

It was too late. Twilight fell into the next page with a dull, papery thud. She lay still, her belly continuing to jiggle for a moment, before she pulled herself to her hooves. "Alright, Moondancer, what's on this page?"

"I'm glad you asked, Twilight! Such a good student, it must be why Celestia chose you!" Moondancer said in a sickly sweet voice, before pointing to the caption below Twilight's hooves, "According to this, obese ponies often suffer from a lack of personal hygiene. Good thing you're such a squeaky clean princess, otherwise I bet you'd be a real stinker!"

Moondancer smirked as Twilight's belly grew once again, the buttons of her shirt popping off one by one, until they just barely covered her sagging cleavage. Her perfectly smooth flesh turned pockmarked with cellulite and streaked with pinkish stretch marks. Sweat stains appeared across her clothing, with splattered food covered her face. Twilight grimaced as a roar emanated from her rear end, accompanied by a smell of musty paper. Along with the fart, the seam at the seat of her pants pulled itself apart, exposing her underwear.

That was when Twilight's face started tingling. Her hands flew to her cheeks, as if trying to hold them in, but it was no use. Her face began widening, puffing as if she were holding her breath, but sagging down instead. A thick ring of fat formed around her neck like a fleshy inner tube, almost touching her shoulders.

The now-massive mare gasped as she blew out another mouldy fart, followed by an unladylike belch. Placing a hand upon the sticky surface of her gut, she realized that even her fingers were fat now. She had to weigh at least 400 pounds!

"O-okay, Moondancer, I get it!" Twilight stammered, through thickened lips, "J-just flip back to the first page and I'll stay out of your hair!"

"Hm, I dunno, Twilight," Moondancer said, taking the corner of the next page between her fingertips, "I wonder what's on the next page?"

"Moondancer, in the name of Celestia, plea- BUUOORP!" Twilight's words were cut off by a deep, bassy belch. Blots of black ink flew from her mouth, representing spittle, and landed all over a nearby paragraph.

"Hey, this is a library book!" Moondancer said angrily, "I guess I'll turn the page and hope nopony notices!" With a wicked smirk, Moondancer flipped the page over.

Twilight let out an aggrieved shout as the next page settled open. Her eyes darted across the paper, searching for the passage that would show her next change... But nothing happened. They were on a blank page between chapters. Twilight could only sigh in relief. At least she wouldn't be getting any bigger!

Moondancer coughed, grabbing Twilight's attention. "You know what, Twilight? I think I'll let you out after all."

"Oh, thank you, Moondancer! Just turn me back to normal, and I promise to go back to Ponyville!"

"Normal? No way, then you'll just come back and bother me." Moondancer smiled at the blobbish alicorn, "But since we used to be friends, I'll give you this choice. Either you leave right now, how you are, or I shut the book and put it back on the shelf."

Twilight knew, if she didn't return her illustrated self to a normal size, her real body would be just as big and nasty. What would her friends think? What would Ponyville think? Worse still, what would Celestia think if she saw her student in this state? A barely mobile blob of a mare, always hungry, always farting, and burping, and eating, and spewing messes all over herself...

But on the other hand, who knew when the next pony would open this book? She was more than halfway through the book, how many ponies got this far in a book about dieting? These books were a dime a dozen, how could she be sure they wouldn't toss it, and by extension her, away when a new fad came around?

Twilight never thought Moondancer could be so sadistic. That smile reminded her of every sociopathic villain she'd ever faced. She knew Moondancer was telling the truth. Either Twilight teleported out now, and was stuck as a morbidly obese slob, or she'd be trapped.

Or would she?

Twilight's plump lips curled into a smile. She could just barely see the letters of the next page through the thin paper. If she could just rearrange them, she could regain control of this crazy situation. The only worry was getting them in the right order, but she was sure she'd get it right. Worst case scenario, she'd spend a few months fasting and exercising in seclusion. A split-second glow of the horn, and she was done. Twilight looked up at Moondancer and smiled.

"Alright, Moondancer, I'll go."

"Thank you," Moondancer sighed, "Just go away and let me study in peace, okay?"

"I'll leave right now, on one condition," Twilight said, pointing to the corner of the book, "You turn to the next page."

Moondancer blinked. "Are you sure?" She asked, deadpan, "It could be something nasty, like health problems. You might have a heart attack, and then I'll have a dead fatass stuck in my book."

"Don't worry, I'm an alicorn, remember? Heart attacks are like indigestion for me."

"Well..." Moondancer bit her lip, "Okay. I don't know what you're playing at, but if it'll make you leave faster, then fine."

Twilight fell with a thud onto the next page, jiggling like a pony-shaped jelly. A nasty fart slipped out with the impact, but Twilight was just glad that her fat ass had broken the fall, hopefully for the last time. Grinning, she got to her hooves and looked around the page for her salvation.

The page was completely blank, with all the words centered around the image box on the side. Some words were covered by others and entirely unreadable, while some were entirely out of line and scattered across the page. It was as if a foal had taken a stamp to a blank sheet. In the center of the mess, scrawled in uneven print, was a single legible sentence.

"Twilight Sparkle... Is... A fat slob." Moondancer read, struggling to make sense of the jumbled sentence, "Twilight Sparkle... Is not... Thin and beautiful."

Twilight's grin turned into an expression of horror. A warm feeling came over Twilight, causing sweat to appear across her body. "No, no, no," Twilight muttered, feeling her insides shift and gurgle. She should've run while she had the chance, but no, she had to try outsmarting Moondancer... If only she'd hired a proofreader-!

There was no time for Twilight to complain, as her body quickly began expanding. Her belly rose like dough, swelling several inches outward while sagging below her waistband. A massive fart thundered out of her widening ass, causing it to jiggle wildly. Her thick fingers were just barely able to undo her belt buckle before her pants shredded completely, leaving her naked from the waist down. She began to wobble in place, feeling lightheaded and off-balance.

Twilight stumbled back, resting against the edge of the illustration box. Gasping for air between belches, she wrapped her arms around the massive, heaving sacks that were her breasts. Crumbs and food stains littered their top, while hot sweat turned the bottom into a slimy morass. At the end, her nipples were as thick as her thumb and half as long, like some kind of disgustingly fat, squishy, delicious... Wait, what? Twilight could barely think, her hands sliding down of their own volition.

Twilight's fingers slid around her nipples and squeezed, sending electric shocks through her body as she gave them an involuntary jerk. A lusty expression came over her face, pinching and twisting her plump nipples. With every orgasmic fart, she jerked them violently this way and that, drops of black ink oozing like milk from her fat teats. Her eyes rolled back, her tongue lolled out, and her horn lit up.

All of a sudden, Twilight disappeared in a cartoon explosion. Moondancer blinked in confusion, until she was jolted from her chair by a massive crash behind her. As she spun around in shock, a terrible smell washed over the room. There, standing on the crushed remains of her spare duvet, was the mare she had taken such pleasure in tormenting.

The alicorn, once a prime example of equine beauty, had become a massive, disgusting wretch. Her breasts hung down over her belly, her nipples barely obscured by the remnants of her Carousal Original shirt, framing her boulder-like belly. All that was left below her waist were her panties, whose elastic waistband was just barely hanging on against the tide of flab around her hips. Her fur was matted with sweat and food stains, with bright pink stretch marks visible between the thick hair. Twilight's wings were flabby shadows of their former selves, all muscle seemingly replaced with soft fat. Moondancer couldn't imagine she weighed less than 600 pounds.

Twilight leaned over Moondancer, coating the smaller mare's upper body in greasy sweat as her breasts pressed against her shoulders. She opened her mouth, revealing a set of yellow-stained teeth, and let out a rancid belch. Moondancer's eyes watered as she struggled to hold her breath, but her resistance didn't last long. Her stomach churned as she breathed in Twilight's foul breath.

"Dat wash fun, Moondanshew!" Twilight said, her fat face slurring her words, "Now it'sh my turn! Get weady to leawn about fwiendship!"

Clean version

Author's Note

Edited version without heavy slob elements. Some belching and sweat; Nothing more.

Clean version

"Did... Did you just teleport into my book?" Moondancer said, rubbing her eyes.

"Yep! It's a special studying technique called the Haycartes' Method. Princess Celestia taught it to me, and if you'll just let me, I can teach it to you too!"

Moondancer stared at Twilight. The alicorn had become nothing more than a cartoonish illustration, albeit one that could move and talk. With a spell like that, Moondancer knew she would never have a moment's peace. Twilight could go into any book and bother her until she submitted, at least to a conversation. She'd follow from page to page, her annoying voice commenting on every sentence, every fact, every-

That's when Moondancer had an idea.

"Twilight," She asked, "Do you know what book this is?"

The sketchy alicorn glanced down at the caption just beneath her hooves. "The average pony weighs around 60 kilograms... Is this a diet book?"

"Yep. And if you'd take a look at the chapter title..."

"Effects of... Obesity... On the equine... Body..?" She read aloud, "What's that got to do with- Woah!"

Twilight yelped as the page suddenly flipped, sending her stumbling head over heels onto the next page, where she landed flat on her back in an illustration box. She got up and dusted herself off, glaring angrily at Moondancer. "You could've at least warned me!"

"Whoops, sorry!" Moondancer said sarcastically, "I was just so excited to read this next page!"

"High calorie intake... Combined with lack of exercise... Causes weight gain..." As Twilight read, her stomach began to grumble. "Moondancer, what's-" She started, before wincing as a strange feeling took hold in her belly. "Woah!" She gasped, her belly suddenly surging forward. Her flat belly filled up like a water balloon, hanging over her waist. Her shirt became untucked, revealing the lower quarter of her gut for anypony to see. Twilight stared down at her chubby frame, then looked up at the giant pony above her. Moondancer reached down and poked her sketched belly, causing it to jiggle.

"Moondancer, this is childish," Twilight said, unamused.

"What's that, Twilight?" Moondancer chuckled "You want me to turn the page?"

Twilight's eyes opened wide. "No, wait a second-"

It was too late. Twilight fell into the next page with a dull, papery thud. She lay still, her belly continuing to jiggle for a moment, before she pulled herself to her hooves. "Alright, Moondancer, what's on this page?"

"I'm glad you asked, Twilight! Such a good student, it must be why Celestia chose you!" Moondancer said in a sickly sweet voice, before pointing to the caption below Twilight's hooves, "According to this, obese ponies find it difficult to exercise due to their size. Good thing you're such a diligent princess, otherwise I bet you'd be a real tub of lard!"

Moondancer smirked as Twilight's belly grew once again, the buttons of her shirt popping off one by one, until they just barely covered her sagging cleavage. Her perfectly smooth flesh turned pockmarked with cellulite and streaked with pinkish stretch marks. Sweat stains appeared across her clothing, while dried food stains covered her face. Twilight grimaced as her jeans grew tighter and tighter, until, with a loud rip, the seam was torn apart by her flabby backside, exposing her taut underwear.

That was when Twilight's face started tingling. Her hands flew to her cheeks, as if trying to hold them in, but it was no use. Her face began widening, puffing as if she were holding her breath, but sagging down instead. A thick ring of fat formed around her neck like a fleshy inner tube, almost touching her shoulders.

The now-massive mare let out an unladylike belch. Placing a hand upon the sticky surface of her gut, she realized that even her fingers were fat now. She had to weigh at least 400 pounds!

"O-okay, Moondancer, I get it!" Twilight stammered, through thickened lips, "J-just flip back to the first page and I'll stay out of your hair!"

"Hm, I dunno, Twilight," Moondancer said, taking the corner of the next page between her fingertips, "I wonder what's on the next page?"

"Moondancer, in the name of Celestia, plea- BUUOORP!" Twilight's words were cut off by a deep, bassy belch. Blots of black ink flew from her mouth, representing spittle, and landed all over a nearby paragraph.

"Hey, this is a library book!" Moondancer said angrily, "I guess I'll turn the page and hope nopony notices!" With a wicked smirk, she flipped the page over.

Twilight let out an aggrieved shout as the next page settled open. Her eyes darted across the paper, searching for the passage that would show her next change... But nothing happened. They were on a blank page between chapters. Twilight could only sigh in relief. At least she wouldn't be getting any bigger!

Moondancer coughed, grabbing Twilight's attention. "You know what, Twilight? I think I'll let you out after all."

"Oh, thank you, Moondancer! Just turn me back to normal, and I promise to go back to Ponyville!"

"Normal? No way, then you'll just come back and bother me." Moondancer smiled at the blobbish alicorn, "But since we used to be friends, I'll give you this choice. Either you leave right now, how you are, or I shut the book and put it back on the shelf."

Twilight knew, if she didn't return her illustrated self to a normal size, her real body would be just as big and nasty. What would her friends think? What would Ponyville think? Worse still, what would Celestia think if she saw her student in this state? A barely mobile blob of a mare, always hungry, always belching, and eating, and leaving messes all over herself...

But on the other hand, who knew when the next pony would open this book and let her out? She was more than halfway through the book, how many ponies got this far in a book about dieting? These books were a dime a dozen, how could she be sure they wouldn't toss it, and by extension her, away when a new fad came around?

Twilight never thought Moondancer could be so sadistic. That smile reminded her of every sociopathic villain she'd ever faced. She knew Moondancer was telling the truth. Either Twilight teleported out now, and was stuck as a morbidly obese blob, or she'd be trapped.

Or would she?

Twilight's plump lips curled into a smile. She could just barely see the letters of the next page through the thin paper. If she could just rearrange them, she could regain control of this crazy situation. The only worry was getting them in the right order, but she was sure she'd get it right. Worst case scenario, she'd spend a few months fasting and exercising in seclusion. A split-second glow of the horn, and she was done. Twilight looked up at Moondancer and smiled.

"Alright, Moondancer, I'll go."

"Thank you," Moondancer sighed, "Just go away and let me study in peace, okay?"

"I'll leave right now, on one condition," Twilight said, pointing to the corner of the book, "You turn to the next page."

Moondancer blinked. "Are you sure?" She asked, deadpan, "It could be something nasty, like health problems. You might have a heart attack, and then I'll have a dead fatass stuck in my book."

"Don't worry, I'm an alicorn, remember? Heart attacks are like indigestion for me."

"Well..." Moondancer bit her lip, "Okay. I don't know what you're playing at, but if it'll make you leave faster, then fine."

Twilight fell with a thud onto the next page, jiggling like a pony-shaped jelly. A light belch gurgled out with the impact, but Twilight was just glad that her fat ass had broken the fall, hopefully for the last time. Grinning, she got to her hooves and looked around the page for her salvation.

The page was completely blank, with all the words centered around the image box on the side. Some words were covered by others and entirely unreadable, while some were entirely out of line and scattered across the page. It was as if a foal had taken a stamp to a blank sheet. In the center of the mess, scrawled in uneven print, was a single legible sentence.

"Twilight Sparkle... Is... A fat blob." Moondancer read, struggling to make sense of the jumbled sentence, "Twilight Sparkle... Is not... Thin and beautiful."

Twilight's grin turned into an expression of horror. A warm feeling came over Twilight, causing sweat to appear across her body. "No, no, no," Twilight muttered, feeling her insides shift and gurgle. She should've run while she had the chance, but no, she had to try outsmarting Moondancer... If only she'd hired a proofreader-!

There was no time for Twilight to complain, as her body quickly began expanding. Her belly rose like dough, swelling several inches outward while sagging below her waistband. Her damaged pants began to pull apart around her widening ass. Her thick fingers were just barely able to undo her belt buckle before her pants shredded completely, leaving her naked from the waist down. She began to wobble in place, feeling lightheaded and off-balance.

Twilight stumbled back, resting against the edge of the illustration box. Gasping for air between belches, she wrapped her arms around the massive, heaving sacks that were her breasts. Crumbs and food stains littered their top, while hot sweat turned the bottom into a slimy morass. At the end, her nipples were as thick as her thumb and half as long, like some kind of disgustingly fat, squishy, delicious... Wait, what? Twilight could barely think, her hands sliding down of their own volition.

Twilight's fingers slid around her nipples and squeezed, sending electric shocks through her body as she gave them an involuntary jerk. A lusty expression came over her face, pinching and twisting her plump nipples. With every orgasmic belch, she jerked them violently this way and that, drops of black ink oozing like milk from her fat teats. Her eyes rolled back, her tongue lolled out, and her horn lit up.

All of a sudden, Twilight disappeared in a cartoon explosion. Moondancer blinked in confusion, until she was jolted from her chair by a massive crash behind her. As she spun around in shock, a smell of lavender washed over the room. There, standing on the crushed remains of her spare duvet, was the mare she had taken such pleasure in tormenting.

The alicorn, once a prime example of equine beauty, had become a massive, disgusting wretch. Her breasts hung down over her belly, her nipples barely obscured by the remnants of her Carousal Original shirt, framing her boulder-like belly. All that was left below her waist were her panties, whose elastic waistband was just barely hanging on against the tide of flab around her hips. Her fur was matted with sweat and food stains, with bright pink stretch marks visible between the thick hair. Twilight's wings were flabby shadows of their former selves, all muscle seemingly replaced with soft fat. Moondancer couldn't imagine she weighed less than 600 pounds.

Twilight leaned over Moondancer, coating the smaller mare's upper body in greasy sweat as her breasts pressed against her shoulders. She opened her mouth and let out a long, warm belch. Moondancer's eyes watered as she struggled to hold her breath, but her resistance didn't last long. Her stomach churned as she breathed in Twilight's grease-scented breath.

"Dat wash fun, Moondanshew!" Twilight said, her fat face slurring her words, "Now it'sh my turn! Get weady to leawn about fwiendship!"