Some trainers were good at battling. Some excelled at contests. Others even used their pokemon for search and rescue.

Riley, though, was good at breeding pokemon.

A year spent at a prestigious daycare and he’d already risen through the ranks, noted for his diligence in getting the eggs and in the easygoing manner with which he handled pokemon. The young man had a sort of charm about him which made almost any pokemon take to him, and he could always get them to cooperate.

One day, after a sudden storm scared all the pokemon inside (except a few rambunctious Water-types) Riley realized that one was missing: Sylveon.

The Fairy-type was a mainstay at the daycare, and one of Riley’s favorites—he was always playful and a little bit mischievous, but usually willing to cooperate with breeders in the end. (Of course he was: the little scamp was utterly insatiable, and one of the most prolific breeding pokemon they had available. Sylveon not being horny was like the sun not being hot.)

Cursing, Riley wandered out into the storm, calling out for Sylveon. His voice barely registered over the gusting winds and pounding rain, and after a few minutes of fruitless searching, he cursed and ducked inside a shed on the property.

The shed’s door creaked in the weather, and Riley huddled against the wall. The shed was almost completely empty, nothing but a sparse square with four wooden walls. Shuddering, he rubbed himself through his wet clothes, hoping he could warm up a bit…

And warm up he did. As he rubbed, heat blossomed in his belly like a flower and slowly spread out over his body. It felt like someone was rubbing a warm towel over his skin. Almost without meaning to, his rubs got slower, deeper, more sensual. Biting his lip, feeling the blush burn in his cheeks, he coursed his hands across his arms, his thighs, his tits—

Wait, what?

Eyes snapping open, Riley stared down at himself. Even with his clothes still on, he could see the shape of his body had changed beneath them. Hurriedly shucking them off, he couldn’t help but gulp.

Small but pert breasts, increasingly plush thighs, and smooth arms—he had a woman’s body. What was more, he appeared to still be changing—he watched his breasts grow a bit more, his nipples darken and grow harder and more sensitive. Even his hair began to spool out.

“What’s happening?” he asked, and then gasped. Even his voice had changed, becoming a higher and softer register.

What else had changed?

Riley almost didn’t dare look, but after building the bravery, one glance confirmed it:

She had a cunt now.

Staring at her own slit with shock and flushed cheeks, her body still softening and transforming around her, Riley didn’t notice as other things began to change. She was shrinking, for one; getting smaller and smaller. Her fingernails were growing harder, almost claw-like. The palms of her hands and feet thickened as she grew pads.

But she finally noticed when soft, yet thick, brown fur sprouted around her wrists and ankles, overtaking her paws—paws, since when were they paws?—before slowly creeping up her limbs. She swatted her legs as though she could beat it away, crying out and feeling the slight hint of cute, small fangs in her mouth as she did so. Similar fluff of a creamy white color began pluming out around her neck and collarbone.

“What’s happening?” Riley wailed, her own voice foreign to her.

As if in answer to her cry, the door to the shed creaked open. Silhouetted in the frame was a familiar figure: Sylveon, the very pokemon Riley had come out here to find.

“Sylveon,” Riley said with relief, trying to stand—and failing on her faltering paws. By this point the mahogany fur had climbed almost to her upper thighs. “You’re here, I was so worried… help me back to the center!”

But Sylveon merely smirked and, with one of his many feelers, pushed the door shut.

With the room shut, Riley was suddenly aware of certain… scents. Sylveon was musky, the same smell he gave off when he was about to breed a female. As he got closer, Riley gulped when she recognized the vibrant red cock bouncing between his legs.

“Sylveon,” she said, her voice wavering, “there’s, uh, n-no females for you to mate with here…”

But even as the words left her mouth, she realized it wasn’t true. Short stature. Brown fur. A floofy creamy mane around her neck.

An Eevee. She was becoming a female Eevee.

“W-wait,” she said, licking her lips, feeling her rough tongue glide over her mouth. Sylveon was closer now. His knot was on full display. “Sylveon…” Her ears, long and vulpine, twitched in anxiety. Against her own will, her pussy slicked up, her own scent joining Sylveon’s overpowering musk.

There wasn’t a mirror, but she was still at least partially human, she thought. If she could escape before Sylveon rutted her then maybe…!

But her dreams of escape would be Riley’s downfall. Two of Sylveon’s long ribbon-like feelers shot out and, while she was distracted, bound her up tight. One of them grabbed her forepaws and tied them together, while the other sunk down to her loins and…

Despite herself, Riley let out a low and heavy moan as the soft touch of Sylveon’s feeler traced itself over her folds. Back, and forth, and back again—it inched with such maddening slowness, drawing out the sensation, that she couldn’t help but whine.

Dimly she was aware of Sylveon standing over her, the look on the pokemon’s face as pleased and excited as any other time she had seen him about to mate. She realized that the pokemon—whom she had once been much taller than—was now about the same size as her.

Something told her she was only going to get smaller from there.

“Wait, Sylveon,” Riley said, or tried to—her words came out all jumbled as she now yipped and purred, like any good Eevee. Ignoring her, Sylveon straddled his pinned paramour, placing his forepaws on either side of Riley’s head while angling his cock towards her warm and waiting pussy.

No longer able to form words, Riley released some vague, half-hearted protesting whine—and then with a short bark, Sylveon surged forward and claimed his newest mate.

Riley’s virgin hole parted for the Fairy-type’s cock like a stone parting for a root—it did so, but begrudgingly. She thrashed and whined like any good Eevee did for her first coupling, and Sylveon barked with glee. He held his cock there for a few moments, permitting Riley to squirm around it, before slowly sliding it out. Riley had just enough time to sigh with relief, her tail twitching in appreciation (tail? since when did she have a tail?) before he slammed it back inside.

His pace wasn’t fast—for a horny beast, at least—but it was still more than Riley could handle. Every thrust of his cock seemed to send electric energy arcing through her, and she wailed and whined with pleasure, the sounds encouraging Sylveon to pick it up even more. Soon Riley’s entire body was shaking as he fucked her with an increasing tempo, tongue lolling in pleasure at how deliciously tight her hole felt around his cock.

Riley’s worst fears were realized—her mating by Sylveon was exacerbating her transformation. The more Sylveon rutted her, the faster the fur spread across her body, and the thicker it grew in. Her voice grew higher and higher, her limbs shortened and solidified themselves in shape, her tail grew bushy, wagging of its own accord—and most maddeningly of all, she continued shrinking, that she might be the same size as any other smaller pokemon.

That meant that her tunnel grew tighter, even with Sylveon’s cock still in it.

As one last anti-growth spurt sent her finally regressing into the small and petite Eevee she had been on her way to becoming, her pussy grew tighter than it had been when Sylveon had first fucked her, even though his cock was still within her. The sensation made her vision blur, and she was distantly aware of Sylveon’s short chuffs of triumph before the insatiable Fairy-type fucked her even harder.

She was an Eevee now, and could do nothing but wait until he was done. His scent and her own burned in her nostrils, making her mind haze, and raw pleasure surged through her like a river as Sylveon continued having his way with her. A low purr broke from her throat, and during those times when he held his cock inside of her, she wriggled around it.

Finally, with one last bark, Sylveon tightened his grip around her forepaws, used his other feelers to spread her legs as far as she could stand, and slammed in, burying his knot in her folds. For a moment, she thought she might pass out.

The Eevee who had once been Riley felt Sylveon cum inside of her, and behind her panting, glossy-eyed exertion, she was vaguely aware that she would probably soon give him eggs. Even now, some tiny part of her wanted to be aghast—but the rest was gliding along in post-coital bliss. If this was to be the new norm, at least she wouldn’t want for a decent lay.

Sylveon wouldn’t let either of them go out into the storm, and it didn’t let up until the following morning. While they rode it out, he made sure to ride out his new breeding partner—over and over and over again.

A few hours after dawn, Sylveon returned to the daycare with the new Eevee in tow. The workers weren’t sure who she belonged to—probably the paperwork had been lost by Riley, who appeared to have quit without notice. Still, life continued at the daycare; pokemon came, pokemon went, a few stayed long-term, and Sylveon, a mainstay there, paid close attention to all his favorites, including the brown-furred newcomer.

Some pokemon were good at fighting. Some excelled at contests. Some were even used for search and rescue. But the new little Eevee?

She was very, very, very good at breeding.