Splinter groaned happily as he lazed in his own immensity. Only one month ago he'd been a slim, athletic rat. How long ago that all seemed. Now he could barely turn his head thanks to the thick tire of neck-fat that he sported, his massive melon-cheeks pressing into it every time he tilted his head. His heavy double-chin bounced as he looked around, the rat gazing down at his sloping mountains of moobs and the immense heaving belly beneath them. He truly was a blimp of a rat now...

It had all started with a seemingly minor accident. One day Splinter had wandered into Donatello's room while the turtles were off on patrol. He liked to do this now and again, to make sure his boys weren't hiding anything from him. Though, with how messy Donnie's room was, it would be hard to tell. Almost every surface was covered in trash, tools, or half-finished experiments. It was a wonder the turtle could find anything at all in this mess!

Splinter had just finished looking around when, as he headed for the door, he accidentally bumped a table. It was an unusually clumsy move for the rat, and it set off a minor avalanche of tumbling trash and equipment. The rat turned and watched as a huge tower of debris teetered, and then started to tip!

Splinter let out a small squeak of surprise and threw his arms open, catching the leaning tower of trash and struggling to keep it from toppling. A few odds and ends bounced off of him and to the floor, but with how messy Donatello's room was it was impossible to notice them. Something slipped into Splinter's robe as well, but the rat didn't notice it among all his panic.

With a heave, Splinter managed to right the pile of stuff he'd disturbed. He let out a sigh of relief and fixed his robe, not noticing the small wet spot in his fur or the odd tingling there. He simply turned and hurried out of the room before he could cause any more trouble, hoping his son wouldn't notice his intrusion. He never noticed the empty vial labeled 'MUTAGEN: DO NOT TOUCH' that he'd spilled on himself, not even as it fell out of his robe and to the floor.

The next few days were pretty mundane in the lair. The same routine of training and working and patrolling for the turtles, and a similar routine for Master Splinter. Of course, he didn't go out on patrol himself, spending his free time tidying up or meditating. He always found great peace in his private sessions.

More and more, though, Splinter found himself wandering into the kitchen. He ate very simple and plain foods most of the time, but as the week went on he found himself craving larger and larger portions. He was embarrassed to find himself needing seconds, or even thirds, every time he ate! He wasn't surprised to find himself a bit thicker around the middle one morning, blaming it on his overindulgence and deciding to control himself better.

With a bit of self-discipline, the rat kept himself out of the kitchen. He hoped it would help, but as he sat and meditated in his room, his belly would churn and gurgle hungrily. It was like he hadn't eaten in weeks! It was getting harder and harder to reign himself in. He felt ridiculous, unable to control his hunger and growing so soft and flabby.

It didn't even seem to stop his growth! The rat noticed his belly protruding more and more each day. He was in denial for the first few days, explaining his slowly rounding belly as a bit of gas or the like. However, as the week ended, the rat was unable to ignore his rapidly forming pot-belly. He was getting fatter, and fast.

It was almost impressive, the rat's slim midsection now a tubby mound of lard. It was far from enough to be called 'obese', and while he was wearing his robes it was almost impossible to notice, but the rat felt it wobble softly with every step he took. He found himself running his hands along it more and more often, blushing as he felt his soft middle give beneath his fingers.

The rat's growth didn't stop a slight pot belly, though. As he entered his second week of growth, Splinter began to notice an odd warmth around his middle. At first he attributed it to his increased size, but as he watched himself in a mirror one morning he noticed a slight movement. He was actively growing!

It was barely noticeable, but it was clearly there. The rat was able to watch as his belly gently grew wider and softer, every few minutes adding a few pounds to his frame. It was quite a worrying discovery, the rat realizing there was something more than a bit of overindulgence going on. He still had no idea what could be causing it though.

So Splinter did all he could to keep himself from getting bigger. He ate less and less, almost as if he were fasting, but it seemed to have no real effect. He spent his free time exercising instead of meditating, but all that managed to do was get him sweaty and jiggly. Working out got harder every day too, as the pounds really began to pile on. And his robe was starting to round out visibly, the rat more and more concerned his sons would notice.

Half-way through the second week. Splinter found himself unable to cinch his robe tight enough to hide his belly. It still wasn't very large, but he had a clear gut now. He'd grown thicker elsewhere too, his rump and limbs all sporting a new flabby layer. He knew he wouldn't be able to hide himself any longer. His sons were not blind.

It took a lot of courage for the rat to gather his sons and then let them know what had happened. He let his belly hang out of his robe and even showed his sons that slow, steady growth he was dealing with. The four were all shocked, to no surprise, but Michelangelo seemed to think it was very funny. He got a good whap on the nose for that.

Donnie went to work right away to discover the growth's source. His first few hours of testing seemed hopeless, until the rat finally fessed up to his little mishap in the turtle's room. After that, it was just a matter of searching the floor for something that might've fallen onto Splinter, and from there Donnie easily found the empty vial of mutagen.

Splinter had accidentally spilled a growth encouraging mutagen on himself, Donnie explained, and that was why he was getting bigger even without eating more. His caloric intake didn't even matter, the turtle went on to add, the mutagen doing all the growth itself. Splinter was happy to hear his son knew what had happened and even happier to hear he didn't have to diet! He'd been starving himself for days, and when his son let him know he could eat as much as he liked, he did just that.

At first, the rat took all his meals in private. He didn't want his sons to see how much of a hog he'd become, let alone have them watching as his belly grew ever larger. It was so soft and ponders now, settling warmly in his lap as he sat cross-legged to meditate. It felt so heavy, so... unnatural.

But, as the days went on and Splinter found himself growing ever bigger, he found himself worrying about his size a bit less too. Eventually, he even began to join his sons for his meals, if only because he could get seconds and thirds easier from the kitchen.

Every family meal turned into half supper, half spectacle as Splinter ate more and more with each passing day. The bigger he grew, the hungrier he got, and he was packing away enough food for four before long! Just as Donnie had said, his gorging didn't affect his growth, the rat continuing to swell slowly and steadily despite his ever-larger meals.

Things returned to some sort of 'normal' after that, Splinter continuing to train his sons even as his waistline expanded. He soon had to wear his robe open all the time, broad belly hanging half-way to his knees and his heavy moobs settling softly atop that massive gut. At least, with his massive backside growing softer every day, meditation was getting even comfier than before!

Waking up every morning to find himself larger and lardier was such an odd experience for the rat, but as he looked himself over in the mirror each day he found himself liking what he saw more and more. His face looked so friendly with its soft, round features, and his plush body served to make the rat feel comfortable no matter where he was resting.

He was even starting to feel a bit proud of his size, thumping his belly now and again after an especially big meal. Mikey certainly seemed to like that, cheering his Sensei on as he ate, and ate, and ate... At first the rat had chided his son, but as he continued to eat and grow, he couldn't help but smile a bit any time the turtle urged him to eat another serving.

By the beginning of the third week, Splinter had gone from fat to massive; a wobbly wall of rotund rodent wide enough to fill a doorway on his own. His massive gut hung well past his knees and rapidly approached the floor. Every slow, heavy step the rat took sent his whole body into wild jiggles; cheeks, chins, moobs, gut, and rump all wobbling in unison. It was rare to see the rat's fat not in motion, he was just so soft and bouncy.

Training had been put on hold, for now, as Splinter was getting far too large and slow to keep up with his sons. More than that, he was getting too big for them to practice against! Any attempted tackle or take down was lost in a sea of soft, supple blubber. The rat missed being active, in part, but he was also thankful that he didn't have to haul himself around as much. It was getting to be a bit of a chore.

Splinter was left with more time to meditate and rest, and he had to admit he was liking it. A leisurely life was not something he ever saw himself living, but as his weight climbed higher and higher he found himself taking to it quite easily. Even his demeanor grew more relaxed, taking on a friendlier role with his sons.

The first time Splinter had accepted Mikey's challenge of a pizza-eating contest the turtles had been shocked! So had Splinter, to be honest, but it seemed like a fun little thing to do. Not like it was going to make things any worse anyways! Of course the rat won, and he was shocked to find himself honestly proud as he did! His ability to eat was becoming a source of confidence, and he couldn't help but feel like he was showing off a bit with his increasingly massive meals.

By the beginning of the fourth week, Splinter was nearly immobile. He spent almost all of his day lounging around and eating, his robe long abandoned as he'd outgrown it. It was a bit odd to be lazing around the lair in the buff, but he grew used to it before long.

Donnie promised he was close to finding a cure, but the rat was in no rush. Part of him had grown so relaxed that he wasn't worried one bit, and part of him, well... Part of Splinter wanted to see just how big he could get.

There was something so luxurious about waking up bigger, and softer, and heavier every single day. The rat began to look forward to his daily weigh-ins, grinning wide as his weight was told to him by one of his sons. They all seemed a little concerned about it all, but the rat was still healthy despite his size at least. That and none of the four could ever remember seeing Splinter smiling so much.

Even as the rat rapidly approached immobility, he was all smiles. He spent hours talking to his sons every day, just relaxing and enjoying their company. He honestly felt more relaxed and comfortable than ever had before, like he was meditating all the time. Though, these days it was mostly napping.

So now, at the end of one month, he'd grown into a massive mound of rat blubber. He was well and truly beached atop his own belly, lazing upon it like some great furry bed. His immense moobs lay atop all that warm, soft bulk, more than massive enough to serve as beds on their own. Mostly, though, they made good arm-rests for the rat's jiggly limbs. He could barely even move his hands now, unable to do much more than grope and squeeze at his own fat.

His fat rat tail hung heavily over his bloated rump-cheeks, not even able to wag during his hourly feedings. His legs were lost to the same fate as his arms, fattened to such an immense degree he was barely able to wiggle them. Not like he was going to be doing a lot of walking though...

Mikey never seemed to stop enjoying the rat's size, coming up with a slew of nicknames for Splinter. Most of them were more than a little silly, but every now and again Splinter felt himself flushing with pride as Mikey made jokes about his weight. He WAS pretty huge, wasn't he? Easily enough to be his own wobbly mountain, like the turtle teased.

He took up a good chunk of the living room at his size, the turtles taking turns tending to him and feeding him through the day. It was an odd arrangement, but it did give the rat more time with his sons. He was getting to know them so much better, and he was truly thankful for that.

Splinter even became a sort of replacement for the sofa, at least for now, as he'd grown so large he'd pushed it out of the room! Leo was still weary about using his father like a seat, but the blobby rat happily explained how it was fine. It actually felt good to have his sons resting against him like that, pressing into his ever-expanding bulk.

Donatello was sure he would find a cure soon, but again Splinter was far from worried. Any time his son brought it up he'd simply smile and nod. In truth, the rat couldn't care less about the cure anymore. He had no intention of ever being slim again, and even if he stopped growing, he'd stay at this blobby size happily.

If Donatello couldn't find a cure? Well, that was even better. There was something so... exciting about the prospect of growing without end. Splinter found himself dreaming about it during his frequent naps. His flab overflowing the lair and then all of New York...

Though, knowing his sons, they'd never let that happen. And that was fine. He was content to stay as he was, or maybe even lose enough weight to waddle around again. As long as he was able to stay soft and warm and comfy, he'd be happy.