Bonus Prompt: Mina and Momo's Moo-sive Upgrade (Patreon)

Tags: Cowtaur TF, Weight gain, Muscle growth, Lactation-udders, MHA

First prompt of the month! This was one that I had started months ago but lost track of. I like to finish what I start, so we will call this a bonus for the month! Sorry if this is a little out there for some of you. I will have some more normal prompts coming up soon.

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"So this will give us new quirks?" Momo asked, staring at the vial which Mina held in her hand.

"Better! This is going to give us Suneater's manifest quirk." Mina played with the small glass tube, slowly shifting the purple liquid inside back and forth. It was strange to think such a small thing could hold such power in it. The formula was power incarnate, a taste of thr power of a member of the Big 3. A simple drink would bestow, for a short amount of time, the manifest quirk of Suneater. "We can make our bodies anything." Mina looked at her friend, eyes wide with wonder.

"Well, anything that we have eaten." Momo corrected, her knowledge of quirks and their uses second only to Izuku. "Still, that's quite amazing." She rubbed her chin, considering it's uses. "With my powers of creation, there would be little that I could not. . ." Momo was cut off as Mina forced the tube onto her lips. The pink, fuzzy haired woman giggled madly as she trickled the serum into her rich, polite friend.

"Yeah!! That's why we're gonna try it!" Mina yelled, carried away by fantasies of what the experiment might breed. "Drrrriiiinnnkk up, Momo!" Mina tried to gauge how much was flowing into Momo, but it was hard to keep track between the jostling and fight for position. Momo had been caught off guard, allowing Mina to play her prank but the other woman was beginning to regain her composure. The two girls struggled until the vial was half empty. Mina backed off, allowing Momo to cough and splutter. The energetic acid spitter sucked the remaining formula down and waited for her friend to stop coughing.

"Aack, what was that?" Momo's usual temperance was broken. "Mina!" She fumed.

"Sorry, sorry!" Mina gave a hollow apology. "I knew you wouldn't do it unless I made you. . ." She tried to look guilty, but lasted only for a few seconds. "Well, what's done is done. Let's try it out!"

Momo sighed, unable to stay mad at her friend. Besides, there was little she could to change what had happened. "What should be try?" She was content to let Mina take the lead. Her serum, her risk.

"Hmmmm. . .how about cows!" Mina suggested, thinking of what she had eaten the most of. "Fluffy, nice, cute, and it's something we've tried a lot of."

Momo considered the suggestion. She ran the idea over in her mind, trying to consider if there were any downsides. Her imagination naturally considered the form and shape of a milk cow. She saw it grazing in a field. It seemed so harmless, a soft creature meant only for grazing and docility. Momo relaxed into the vision, finding it comfortable. However, as her mind wandered, her body began to change.

It started with a ripple spreading through her legs. Even through her white jeans, the slow surge of skin and bone could be seen. Her legs thickened and her bones grew denser. Her butt widened, shoving out against her pants. Momo had become entranced by the images of grazing cattle in her mind, so she was unaware of the tail spouting between her plump buttocks. Even the ripping of her jeans and panties did not awaken her. Momo was lost in dreams about cows, which in turn morphed her lower half. Another set of legs manifested from thin air, ending with perfectly clean hooves. She grew taller, born aloft by her set of four legs. Her panties stretched tight over her bovine lower half, refusing to break. That is, until her udder started to form and bulge. To Momo a cow had a nice, round udder. Pink and fat, it was an organ central to the beast. Hers matched this vision, swinging like a cannonball in a cargo net. The only impediment to its movements were Momo’s chunky cow-thighs, which grew thicker by the moment.

"Heeeey! No fair starting without me!" Mina whined, shutting her eyes tightly to copy her friend. She thought about cows. Mina's mind filled with great herds of them. They ranged free and happy. Their lives upon great plains were rough and they needed constant protection. Mina's vision showed her a tough but reliable breed of cow, closer to the extinct ancestor aurochs than anything living. Her body changed as well. While she grew the same features as Momo, hers were of a distinctly rough and tumble nature. Her four legs were thick with muscle as well as fat. While Momo rose in height, Mina shot upwards in spurts. Her excited breaths turned to snorts, especially as she felt her pants shred away. Mina's grin deepend as she saw her fantasy sharpen. She was not a simple, domesticated milk cow. Rather, she was something more primal. She was the kind of beast that had conquered the early plains. Mina's udder bloomed underneath her, tighter and with less swing. Her hooves pawed at the ground, thumping with latent power. Her fur was shaggy, yet retained its pink coloring. As a final note to her transformation, large horns sprouted from her head.

Finally, the two women opened their eyes and stared at each other. Momo was the first to react. "Aah! Mina!" She clomped backwards, taking uneasy steps on her new hooves. "You're huge." She looked up at the large pink beast. Momo felt a instinctive nervousness, her brain whispering thoughts of flightiness to her. She was only a simple, milky cowtaur; such a beast was beyond her. She backed towards the door of her dorm room until she accidentally out a hoof through it. It was then that she realized her own change. "What happened? Oh my God. . .I'm. . ." Her voice trailed off as she nervously kicked and bucked at the door to free her hoof. She had a black body with white spots. Her body was round and fat, her cow-stomach big enough to almost block the view of her udder. "Minnnaaaaa. . ." Momo whined, her voice coming out almost as a long moo. Her tail twitched unhappily, swishing against the door.

The sound of Momo's whine struck Mina oddly. She felt a physical twinge and shake go through her. She shook her head, trying to free herself from the feeling. There was a compulsion to help her friend, stronger than anything she had felt before. She trotted forward, powerful legs and hooves cracking the floorboards beneath her. "Hey, hey!" She caught Momo’s slim arm on her own. While the two had gigantic cow bodies, they retained their own normally proportioned human torsos. It was disjointed, like two small women had been stapled onto the bodies of beasts of burden. Yet, there was a new sort of strength pumping through Mina. She had little trouble pulling her friend from the door. Momo's hooves and kicks had left the thing a ruined mess, shattered below the halfway point. Mina had eyes only for her friend though. "It's OK, just me." She pulled the black haired woman into a tight hug. Their human stomachs met, as did the front of their cow bodies. Mina brushed Momo's hair with her hand, lulling the other woman into a more settled state. It felt natural to comfort Momo like this, in a way that went beyond the bond of friendship the two already established. It was not simply their bodies that had changed.

Momo sighed, resting her head on the larger cowtaur’s chest. “Thanks, Mina.” She ruffled the other woman’s shirt playfully, enjoying the feeling of the embrace. She could feel her friend's heart pounding, strengthened to handle two bodies fused into one. She knocked a hoof into Momo’s, clacking them playfully. Despite her size and girth, Momo was more than capable of dainty actions. “I kind of lost control for a moment there.” She blushed, burying her face in Mina’s chest further. Her spiky hair swished under the other woman’s chin. “How silly. . .” She sighed, letting Mina comfort her just a little longer. Momo had never been denied love or attention, but this felt extra special in some way. She wanted to curl up next to Mina on a grassy field, their bodies rubbing each other.

“You ok now?” Mina asked, perhaps hoping for an answer other than “yes”.

“I think so. . .yeah.” Momo answered, confirming Mina’s oncoming sense of disappointment.

The two broke apart, studying each other again. Neither was quite sure what to say. The awkward silence provoked them in different ways. Momo to silence and Mina to try and blurt anything out to break the tension. “Gosh! You’re cow body is so chubby, Momo!” She said, blushing at how ignorant and insensitive she sounded. Hiding her shame, she clopped and tromped around the smaller woman. Her hooves dug into the wood floor. “What kind of cow were you thinking of?” Mina tried to make a joke of it, poking and prodding her friend’s rounded cow tummy. Whilst Momo’s human form had stayed slim, there was a definite chub to the rest of her, to say nothing of the immense udder hanging between her legs. Mina, noticing how robust the milk producing organ was, felt another strange twinge jump through her. “I can tell someone wanted to be a milky cow!” Mina bent her torso down, fully wanting to grasp and play with the puffy, pink orb. However, she decided that would be less than polite. She instead rubbed her friends' hindquarters.

“I was just thinking about cute cows.” Playful tears ran down Momo’s cheeks as she fake sobbed. “And cows are supposed to be milky! I don’t know if you got the memo, Miss Shaggy!” She recovered quickly, eager to point out the utter strangeness of Mina’s chosen form. Momo checked a large hip into Mina, her udder swinging back and forth with perilous force. She sucked in air, feeling just how heavy the milk bag was. Her chubby, plump stomach knocked into Mina’s sinewy, bulky side; again showing the contrast between their forms.

“I’m just a free roam kinda gal!” Mina put up her arms in a flex, they were pitifully small compared to her cow body. The two laughed, continuing to poke fun at each other. They trotted around the room, each trying to find the strangest thing about their new bodies. It was funny, trying to understand how their borrowed quirk had changed them both inside and out. The strange serum had granted them an ability that they never would have access to, but it was not meant to last. While powerful, the serum could only last so long. The girls had halved their time by only drinking a portion of it. Now, as they frolicked and explored each other’s bodies, they were running up against the clock. Bit by bit the drug was wearing off. Their new bodies, rather than being a silly joke with an expiration, were becoming permanent. For each minute that passed, their cow parts became ever more solidified and bonded to their genetic structure. Blissfully unaware of the serum’s wearing off, the two played away their final moments of full humanhood.

--- Years Later ---

“Uuuh, could I get 3 of the triple burgers. . .” Momo placed her order, too hungry to recognize the irony of asking for hamburgers. Realization of cosmic humor was reserved for people that did not have 3 stomachs to fill every couple hours. She continued listing food, her back hoof rubbing against her udder. Noon was simultaneously the best and worst time for the hero turned milkcow. She was hungry and filled to the brim with milk. Her body had processed the many earlier feeding, turning each into milk or more fat. Her udder bulged outwards, the already huge organ doubled in size from lack of milking. Oftentimes, it would grow big enough to force her hind legs apart and bounce off the ground. "Sorry, just a little bit more. . .it's all so good." She leaned forward, human gut warming the counter it rested on. Years of indulging her trio of stomachs had led to a literal ton of weight being packed onto the heroine. Both Momo's human and cow bodies had expanded to astronomical proportions. Her upper body evoked a woman nearing 600 pounds. Her cow portion was similarly huge, boasting a gut which dangled ever closer to dragging upon the floor. Momo was a creature built for eating, milk, and comfort.

"That will be all." Momo said, finally finishing an order of biblical length. She waited patiently, wondering why the attendant hadn't put her order in. She stood there politely, trying her best to figure out the current situation. It dawned on her a moment later. "Oh gosh! I need to pay." Her mind clicked into gear and she hurriedly fished around in her bra for her credit card. To make the search easier, Momo simply took out her breasts and searched under and around them. The patrons and workers watched open mouthed as the gigantic cowtaur squeezed and fondled her milky breasts in an effort to pay. Momo merely hummed, blissfully ignorant of the social norms that she was violating. The fast food worker gaped, eyes filled with the vision of cantaloupe sized breasts with vividly red nipples bouncing before her. They were full to bursting with milk, moving with jiggles that seemed too thick and slow to be real. “Ah! Here it is.” Momo finally found her wallet, decorated with chibi cows, and handed her cash to the cashier. The transaction was completed slowly, with Momo taking the time to lovingly tuck her breasts back into her top. Momo’s bovine ass smacked against the counter as she slowly waddle-walked her way down to the receiving end of the counter. The excitement of food caused her udder to further swell with milk, almost big enough to drag upon the tiled floor.

It wasn’t that Momo was dumber because of her transformation, rather that simplicity and docility had become the prime directives in her life. The normal desires of life had fallen away. She cared not at all for a career or status. Momo’s interests were eating, fattening up, and producing as much milk as she could. More than ever, she was a sweet creature. She thanked the worker and took her food, ambling out of the store. She ate, shoving the thick meat patties into her mouth with rapturous joy. Her enjoyment grew into verbal and physical enjoyment. She hummed and murmured as she ate, whilst her tail swished and slapped against her ass. It was a pleasure to glut herself at every meal, to fill her multiple stomachs to the absolute brim. Further, this was matched by the knowledge that it would end in another growth spurt. Her bodies would fill and expand, turning her into a more effective milk cow. Momo finished the first burger, fishing in the bag for another. She pressed the grease covered paper to her chest, excited to make the contents one with herself. The immense cowtaur was so in love with her food that she didn’t notice the group of teenagers sneaking up behind her.

“Fattty!” One called.

“Moooooooo! Mooooo!” Another said, their voice sharp and petulant as only a teenager’s could be.

“Why’s a cow even eating meat? That’s unhealthy!” The smartest, and meanest, of the bunch ran up behind Mina and smacked the bag out of her hand. Food splattered everywhere, dousing Momo’s formerly clean coat and sagging gut. Ketchup and mustard doused Momo’s wobbling gut. The burger patties stuck to the front of her cow body before slowly sliding off and landing sadly on the floor.

“Heeeeeey!” Momo drug out her sentence, sadness at the wasted food slowing her mind. “Th-that was. . .sniff. . .mine!” The sensitive cowgirl blinked tears out of her eyes. Tried to reach for the fallen food, not wanting to leave a mess on the sidewalk, but her hooves slipped on the pavement. Momo tripped and tumbled down, falling onto the mess. Her heavy body landed with a thud that shook the surrounding area. The teenages stumbled as they felt the rumble pass through the ground. Momo, bereft of dignity and other options, began to cry. She stroked her long, black hair whilst tears fell from her eyes to splatter on her enormous breasts. Her entire body heaved as she sobbed. She tossed her head back and forth, chins jiggling. As if the experience could not be more embarrassing, one of the gang of teens dumped a cup of soda on Momo’s head. She tried to stand, but the weight of her gut and udder combined with the slipperiness of the sidewalk saw her fall. The teens cheered as the heavy thud shook the ground under them. However, their cheering stopped as the thudding continued. Something else, something big was approaching.

The rumbling grew ever stronger and it was joined by sound of concrete cracking. Their feet shook and wobbled as they felt another person approaching. “HHHHEEEEEEY!” A deep voice snorted over top of the rumbling. “That’s MY girlfriend you are pestering.” The speaker was a woman, but her voice was strained with anger and forced an octave lower than it should have been. The teens tried to turn but most were knocked down by something huge and moving fast. The unluckiest of the bunch was plucked up, lifted high off the ground. He felt hot breath pouring over him as he swang back and forth, his shirt caught on something sharp. Whatever beast or monster had him turned and stopped abruptly, sending him flying into a nearby dumpster. He landed hard, knocked unconscious. Mina Ashido, Terror Bulltaur, had arrived to protect her soft and docile lover.

Mina was bigger and heavier than Momo, as thoroughly changed by the passage of years in her new body. That change, however, took on a decidedly scarier form. Muscled rippled down every last inch of her body. She rippled with what might have been chorded and folded steel. The figure of her human body was comparable to that of All-Might, though possibly bigger in size. She wore a black tank top which only served to keep her heaving bosom from being entirely exposed. The tanktop clung to thick and defined abs, with no fat to them. Mina was bulky and blocky, but had none of the softness that Momo did. Her arms, thicker than telephone poles, were left to flex freely. Her bovine half was equally as muscled. Bulging sinew and viens carrying nothing but aggression chemicals and blood trailed down her legs. Though her fur was pink, it was shaggy and jagged. A tough, lined face stared down at the teens. Mina had a gigantic nose ring, spiked and dangerous as she was. To complete her image, twin horns sprouted from her head.

“Think. . .BBBRRRGGHMMPH. . .it’s funny to harass defenseless heifers?” Mina snorted, stomping a hoof down on the ground. The pavement cracked easily, as it had been made of paper mache. She pawed the rubbed, grinding the pieces further into dust. She looked between the teens and Mina. The fat heifer had started to recover, but was still lightly sobbing. She put her chubby fingers through her wet hair, trying to wring the soda out of it. A bubbling rage spread through Mina as her aggression and adrenaline spiked. Even under normal circumstances she was an aggressive and brutal creature, the teens had just given the excuse to take the reins off. “Better run!” She bellowed, starting to charge again. Her hooves crushed the ground below her as she brought herself up to ramming speed. The boys started to run, but were infinitely too slow. Mina caught them easily, knocking a telephone poll down in the process. She hit one away, sending him flying across the street. She caught the other by his arm, throwing him onto his buddy seconds later. Once that was done she turned back to Momo.

The obese cow whimpered but slowly stopped her crying as she felt Mina approach. Feeling the muscular woman’s hoof-steps set her at ease. She was comforted by the presence of her freakishly muscled lover, now having someone to lead her. That was the way of things now. Momo got to eat and indulge, whilst Mina kept her safe and happy. Without getting up, the hefty woman slid close to Mina. She did not look up, instead demurely looking at the ground. As much as she loved when Mina got to protect her, she felt a bit silly about it. She wrapped thick, blubbery around Mina’s muscled legs. She felt the tension drain out of them. Momo was the only being that could take the aggression out of the pink bull. “Are they gone?” Momo asked, one of her fat legs kicking. It rubbed against her udder, which had only grown more swollen throughout the confrontation. Being around Mina sent her milk production into overdrive. Once, a techy hero had tried to explain why. . .but Momo had been far more interested in eating. “You didn’t hurt them, did you?”

“Pfff, I wish.” Mina snorted, leaning down to rub Momo’s long hair. She had to bow a little bit, but soon her strong hands were squishing her girlfriends cheeks. “You always know how to find trouble.” Mina cracked the knuckles on her other hand, wanting to give Momo more reminders of her strength and power. She would spend entire days at the junkyard bending scrap metal to impress her; Momo cheered with every new bend. “They won’t forget this though. Nobody messes with my herd!” Mina flexed, her biceps rearing up like miniature charging bulls. Veins popped out, again showing the natural musculature she had been blessed with. While she had traded her original powers for these new ones, it might have been an even exchange. She smiled, feeling the wind rush through her wild and untamed mane of hair. She was drawn away from the impromptu posing by the feeling of Momo nosing at her. Seconds later, Mina was giggling and stomping as Momo latched her soft mouth to her udder. “M-Momo! Not in public!” Mina gasped as she felt a soft mouth latch around one of her teats and begin to drain her of milk.

Momo smiled as warm, fresh milk poured into her mouth. Whilst Mina’s milk was blander and less sweet than her own, there was none that she would have rather had. One of her many stomachs began to quickly fill with the liquid as it was pumped out. Owing to her active lifestyle, Mina’s udder was humbler in size. It was no industrial milk tanker like Momo’s, but was at least around the size of a normal udder. She took huge sucks, stopping only to rub and pat Mina’s flank. “Mmmrrrrroooooooh, please Mina!” Momo mooed the words out. “I wanted to have that milkshake. . .but they spilled it.” Momo went back to suckling at Mina’s udder. Her own grew from the excitement, swelling outward such that it began to lift up one of her legs. A tightness was forming within her udder, starting to reach a critical fullness. She would need to be milked soon, but that could wait. “Your milk helps me grow so much!” Momo giggled. “I want to be as big as possible for you.” Her chubby hand playfully tugged at Mina’s swishing tail. “Don’t you want a fat, roly-poly heifer to squeeze and milk?”

Mina bit her lip. She stomped a foot on the ground. While new potholes were dug under that strong hoof, all Mina could feel was a set of plump lips around her udder. “Moooooooo. . .Pfffffffhhhp. . .fine!” Mina moo’d and snorted, falling victim once again to the little beggings of her girlfriend. She crossed her arms and squatted down a bit, allowing Mina to have a better angle for her obscene activities. People pointed and whispered, making Mina blush. Her hackles rose whenever she felt like she was becoming a sideshow. The urge to charge rose and fell in time with the pleasure that Momo was able to dispense to her. Through it all she envisioned her girlfriend swelling and growing, becoming the fattest cow on the planet. “You had better get really big because of this.” She snorted, blowing a lock of hair out of her eye. Mina fiddled with her nose ring, thumbing the sharp point at the end.

“I will. . .I will!” Momo whispered, putting a hand down between her latter set of legs. She felt the swelling udder and belly. Knowing that everything she ate would either turn to milk or fat. “And you are going to get every drop of milk I make!”