A/N: Oh hello, I'm chip! I'm importing my fics from AO3 to here just in case people prefer the format here. Anyway's here's a oneshot I made based on a random horny thought I had. This is mostly just world building with a hint of smut.

Summary: Hybrids. The thought of one existing in this human-dominated world seems impossible, comical even. But Toshinori was going to prove the whole world wrong with his discovery of Izumi.

CW: Genderswaped Izuku (Izumi), details of going into labor, blood mention, mild dubcon

It was just another normal day at the Yuei Wildlife Rehabilitation Center for the senior veterinarian Toshinori. Taking care of the new weak animals that came in, giving his assigned animals their meals throughout the day, and studying any changed behaviors from the animals that are recovering. Just the usual stuff he'd do on a regular day.

After he clocked out, Toshinori always did a quick checkup around the place before he left. His coworkers insist it wasn't necessary as they always double-check everything before they leave, but he insisted on doing a final run around. As walked around the area, he mentally checked off all of the different pens. 'Everything seems to be in order…' he thinks to himself once he walks past the cat pen with All Might the three-legged lion sleeping inside.

Toshinori suddenly stopped in his tracks when he saw someone a few feet away try to climb up the tall fence of the cat pen. The warm-toned street lamps were poorly lit, but the silhouette made him tilt his head in confusion. The person had a tail, ears, and hind feet, just like a cat. Was this a prank from his team? No...it couldn't be, right? His coworkers weren't the type to prank at work. Before Toshinori could step forward, the shadow seemed to notice his presence and ran off in a different direction.

Toshinori followed the shadow and took out his phone to turn on the flashlight app. Once turned on, he quickly flashed the bright light in front of the intruder, who halted, turned around, and stared him down with their piercing green eyes. Toshinori was speechless at the sight in front of him. Their entire body was unnatural for a human, both in shape and color. Other than their torso and face that was of a normal skin tone and human-like; their arms, legs, cat ears, and hair were a forest green color. Their tail was raised and frizzled, their sharp claws were out, and their ears were down; ready to defend themselves. Just like a real cat.

Toshinori blinked his eyes a couple of times to make sure he wasn't hallucinating. But they were still there; still ready to attack if he dared tried to threaten him. Perhaps this was just the power of special effects makeup and this person wanted to camp out here for the night to live their inner feline? Maybe, hewasn't too sure. It was the only logical explanation he could come up with on the spot.

"Excuse me, but we're closed for the night, do you need help?" he asked, trying his best to keep his composure. In response, the intruder simply yowled at him.

Toshinori immediately backed away and widened his eyes, his fight and flight scenes beginning to kick in. He hasn't had this feeling since he was working as an apprentice with his mentor, Nana so many years ago. No human could produce that noise and the sound didn't seem to be coming from a speaker, but maybe this person practiced their cat noises for a long time?

"D-Do you speak Japanese?" he asks, his tone still soft and calm. He then switched to his secondary language as he took another step forward. "O-Or English?"

All he got back was a quick warning hiss. Talking to them seemed to be pointless.

Suddenly, Toshnori got an idea, it seems stupid, but maybe he could ease the tension if he played this person's game.

Slowly, he put his phone in his pocket, the street lamps from afar being the only source of light he had now. He then took off his backpack and got a small plastic bag of his leftover Goldfish crackers, poured it out onto his hand, and offered the treat. "This has to be a prank," he thought to himself as he imagined an amateur cameraman hiding in the bushes this encounter.

Slowly, the other hesitantly walked over to Toshinori's hand, sniffing at it curiously once they were close enough. They looked up at him for a moment, seemingly still in a defensive state before quickly eating the snack.

"You must have been really hungry..." Toshinori softly says to himself as he watched them lick at his hand to savor the small amount of excess cheese and salt from the crackers, noticing the sandpaper feeling on his palm. Okay, you definitely can't fake that with effects makeup, unless maybe this person conventionally was born with a rough tongue? That can happen to a human, right?

Once all of the food was gone, the intruder backed away and looked up at Toshinori, calmer than before.

"I have more food… in my office," Toshinori says in Japanese, pointing towards the nurses' office hoping the other understood. He then took a few steps back, which the other walked forward in response. He then let out a small shakey sigh to try to calm himself as he began to walk back towards the office, watching the other like a hawk as they followed him.

Once they made it inside the nurse's office, Toshinori turned on the white fluorescent lights which gave him a better look at what he was dealing with. Despite being highly defensive, their body was in no condition to fight. Their ribcage was slightly peaking through their skin and there were battle scars all over their body, mainly the arms; some recent, some old. The person in question laid down on their stomach on the examination table and stretched their body. Their tail moved around aimlessly in the air as they got comfortable on the flat surface. Even with special effects makeup, acting, and electronics combined, there's no way someone could make their make-shift tail move so… seamlessly.

Toshinori cautiously wrapped his hand around the fluffy, white-tipped tail and it felt so real. Way too, real in fact. He then moved his hand to the other's head and lightly played around their green ears, noting how flesh-like it felt. Toshinori backed away and looked at the intruder in disbelief, shaking his head. He began to come to terms with what he just discovered as he watched the other look at him curiously, probably waiting for the food they were promised. This wasn't a cosplayer or his imagination playing tricks on him.

This was a real cat hybrid.

After taking a breather, Toshinori petted the hybrid on their head, which made them purr. He began to wonder about the hybrid's origins. Did a human finally manage to get pregnant with animal semen, or visa versa? Was this hybrid used to be human but their limbs were replaced with animal parts and how did they escape from their experimenters? Was this done on purpose perhaps as a social experiment? All of his possible theories seem silly, but the thought of a real hybrid alone was silly. He sighed and decided to focus on doing some bloodwork and bringing this hybrid to normal health. It was the least he could do for now until he gets the right people involved.

This was going to be a long night.

Toshinori began to do a series of tests that night. Other than dehydration and hunger, the hybrid was fine based on the checkup he did and x-ray scans. During his online research, Yagi didn't find any reports of hybrid sightings; not even rumors of one. That wasn't much of a shock, it was ridiculous for society to believe such things; the thought of hybrids kind was just purely fiction, only seen in cartoons and fanfiction.

Throughout the testing phase, Toshinori found himself calling the hybrid Izumi. He didn't know why exactly, they just looked like an Izumi to him. The veterinarian found out a few other characteristics of Izumi such as that she was female, her claws could retract, she had six functional breasts like a normal cat, and that, when on her good side, Izumi was a calm and sweet cat. He wondered if Izumi could get along with the regular cats… he'll have to see in the morning.

By the time four o'clock hit, Toshinori placed Izumi into quarantine and passed out on his desk.

"Yagi? Yo, Yagi wake up!"

Toshinori groaned as he felt someone shake his shoulder. He sat up to see a shocked Yamada hovering over him. Sitting up from his chair and stretching his body he looked at the clock and realized it was six in the morning, the time that most of his coworkers come in and get everything set up for the animals.

The muffled sounds of the hybrid hissing could be heard from his office. Shit, they probably saw Izumi in quarantine and made her scared, assuming that she was some crazy cosplayer that snuck inside.

"Damn, uh, listen, Yamada, I can explain...!" Yagi says tiredly before rubbing the side of his head. "Let me just get her food first," he says before getting up and going over to the refrigerator to get some of the chopped up raw meat that they usually fed the other cats. He placed the chopped up meat in one container and got another container to fill it up with cold water.

"Raw meat? Yagi, what are you-"

"She's not human, she's a real hybrid," Toshinori simply states, Yamada raising a brow.

"I found her outside last night and I have x-ray scans of her anatomy to prove it…" Yagi explains to the other, but when he turned around, his coworker was still in disbelief. "I'll show the scans later, but let me just feed her real quick, okay?" he says before dashing out of the office and towards quarantine, the blonde following right behind him. The quarantine room that Izumi was in was spacious and had a few toys inside for her to play with. Aizawa just exited the room, a few paper-thin cuts on his arm. "That kid's crazy, I'm calling the police," he says in defeat as he took out his phone.

"Don't! She's just scared and hungry, she had a long night of testing," Toshinori whined, which made Aizawa raise a brow.

"Yagi's sayin' that the kid's a hybrid or something," Yamada explains with a shrug as Toshinori enters the room, keeping his distance from the hybrid. Izumi was huddled up in the corner, dark circles under her eyes as she stared up at Toshinori, making a low yowl.

"It's okay 'Zumi, it's just me. You must be hungry," he says softly, placing the small containers onto the floor. Hesitantly, Izumi sniffled in the air as she crawled towards the food. She then began to eat away, Toshinori getting on his knee to pet her as to calm her down.

"What the hell…" Aizawa muttered as he and Yamada entered the room, watching Izumi eat her lap up her water. "Yagi, are you… into pet play or something? Because this isn't cute at all, you need to keep your fetishes at home-"

"This is serious, Shota," Yagi interrupts before standing back up and facing his coworker wholeheartedly. "I was in disbelief too when I saw her last night but… she's real. I just saw her trying to climb up one of the pens during my walk around so I have no idea where she came from," he explained, his two coworkers still not buying the story.

"Look, I'll show you the scans later, just feed the other animals for now," Yagi instructed. Yamada and Aizawa looked at each other for a moment (probably thinking that Toshinori was going nuts) and shrugged before leaving the room, leaving Toshinori alone with Izumi.

"Oh, Izumi… what are we going to do with you?" he says, Izumi looking up at her caretaker and giving him a small meow.

"Holy shit, so this is real…" Aizawa says in shock as he stared at the x-ray scans of Izumi's legs.

"...Question is though, what do we do with her?" Yamada says as he continues to look at the scan of the hybrid's arms.

"Obviously we have to tell people about this, get a zoologist involved so they can study her behaviors," Aizawa replies, crossing his arms. "Maybe we can give her a separate pen temporarily until we figure out a plan," he says.

"Let's just hope we can convince Torino about this," Toshinori stressed, leaning back in his desk chair. "You know how stubborn he can be…"

At first, their boss was laughing at the thought of a cat hybrid, assuming that they were tricking him or something, but after introducing Izumi to Torino (with Toshinori supervising of course) and showing his x-ray scans, he was just in much shock as everyone else.

Soon all staff members were aware of Toshinori's discovery and they quickly fixed up a vacant pen for Izumi. Her space had a large tree inside that was tall enough to hide within the tree, but not too tall where she could escape. She was also placed on a special diet to help build back up her strength. The staff quickly found out that without Toshinori presence, Izumi was extremely aggressive and territorial. She would not hesitate to scratch and attack them, especially Aizawa for some reason. An inside joke was formed that Izumi didn't like him because she thought that he was trying to put the moves on her. Poor Aizawa, he couldn't catch a break with the jokes during lunch!

During Izumi's recovery, news outlets heard about the hybrid after Yuei's Wild Life's Twitter posted pictures and videos of Izumi. Several interviews were held once she was in better condition and got additional lab tests done. Toshinori was always present in the interviews, either asking questions or presenting Izumi. Some of the news anchors were respectful (or more so scared) of Izumi by keeping their space as they filmed her while others challenged Izumi's legitimacy by putting the microphone up to her face and asked questions to her directly, only to have Izumi sniff curiously into the mic.

With the interviews getting millions of views on YouTube, more people and zoologists alike began to visit the rehabilitation center just to see her. It did give them the funds that the small rehabilitation needed to buy more supplies, but it also caused Torino to create a waitlist to not overwhelm Izumi and the other animals recovering with the spike of guests.

A few months passed and Toshinori was doing his nightly walk around at the rehabilitation center like he always did. He was about to check on All Might when he heard wauling from Izumi's pen. Hearing that familiar sound, he rushed back into the nurse's office to get the necessary supplies.

This was Izumi's first heat.

His team always brought up the idea of getting Izumi pregnant. But neither Izumi nor the male cats seemed interested in mating together despite their friendly interactions with each other. So instead, they tried a more direct approach by injecting the sperm in Izumi instead. Unfortunately, Izumi's body rejected both human and animal semen. A group of biologists been trying to find hybrids like Izumi in the wild to see if maybe her body only accepted other hybrid semen, but no luck so far. Hopefully, they can find one before it's too late.

After getting the blanket, a few play toys, and a heating pad, Toshinori stepped out of his office and sniffed the air. What shocked him when he got back outside was Izumi's scent. Unlike a normal female cat's scent, this scent that Izumi released was… pleasant to smell? It wasn't a urine smell like it normally should be, but more so a lavender smell. He felt so excited to see Izumi for some reason. Maybe it's because he hadn't seen her all day as all of his focus was on the new sickly bobcat that came in this morning? As he got closer, Toshinori started to feel flushed. He wasn't sure why he was just fine a minute ago! Maybe he was just having heat flashes, he knew he should have eaten those spicy chips again!

By the time Toshinori got in the pen, his entire body was feeling so damn hot. Did the temperature outside suddenly rise or something? He'll blast the AC in his car during his ride home once he's done here.

"I-Izumi… I-" he paused and stared at Izumi who was all hot and bothered. She was rubbing her body against the rock she liked to lounge on during the day while people visited her, his ass, and tail up in the air. There was a large amount of slick dripping down her legs and she was drooling from her mouth.

"Al...pha…"

Toshinori dropped all of his stuff and took a few steps. "W-Wha...?" he whispered, shaking his head. He surely was just hearing things. He should lay off the coffee and probably take a few days off, Izumi should be fine on her own. His coworkers found ways to feed and check on her without getting scratched.

"...Alpha…" Izumi repeated once more before she stood up and walked towards the veterinarian.

The thought of Izumi's existence alone was super crazy for Toshinori and the rest of the world to believe but Izumi talking in his language was a whole other level of crazy!

"Izumi… y-you can talk…?" Toshinori managed to say as he stumbled backward towards the door. He tried to take his phone out to record, but the next thing he knew, Izumi pounced him and pinned him onto the ground. The hybrid was surprisingly strong for someone that only weighed one hundred and twenty pounds, but it didn't help that Yagi was extremely skinny and had no upper body strength.

"Breed…" Izumi murmured before she sat up and brought out her claws. She then ripped off all of Toshinori's work uniform in a rushed manner; making a couple of light scratches on his skin as she did so. Yagi was just left with the bottom half of his pants and shoes on.

Izumi's breathing began to get heavy as she grinded her wet pussy against Toshinori's limp cock, her upper paws keeping his wrists pinned down. No matter how hard he struggled, the hybrid kept him down.

"I-Izumi please, get off…" he whined, but the strong scent of lavender brought him into a daze. He wanted this, he wanted this so badly… he wanted to feel how warm his good girl Izumi felt around him… No, what was he thinking? Izumi's a wild animal, even if she did share human characteristics with him. But Izumi wants this so badly, even if she can't get pregnant by him. Izumi needs someone to breed her, just like how Mother Nature intended. But what would his coworkers think when they find out that he allowed this to happen? They'd shame him for sure for being so weak, probably fire him and let the world know how much of a pervert he-

"Alpha…"

Toshinori leaned his head back as he felt the warmth of Izumi's tight and wet pussy. It felt so different from the few women he had been with in the past. Maybe it was the warmth, Izumi's taking charge, or the large amount of slick Izumi was producing, but it felt amazing nevertheless. Like any other animal, Izumi didn't waste any time with foreplay or pacing. She immediately moved her hips at a fast pace, her small breasts bouncing slightly as she did so. Her mewls were loud, excited to finally have something inside of her.

At this point, the scent took full effect on Toshinori's mind as his anxiety about the possible consequences faded away. All he wanted to do was to enjoy this moment with his perfect cat girl and give her all of the milk she so desperately wanted inside of her womb. When Izumi let down her guard and moved her paws to his chest, Toshinori placed his hands on her hips, making sure to keep Izumi's pace going if she dared to try to slow down.

"Alpha! Alpha!" Izumi cheered, leaning her head back, her tongue sticking out as she was getting close to her orgasm. Toshinori admired how beautiful and cute his little kitty looked with the yellow-orange lighting that brought out her best features.

With one final thrust, Yagi kept still as he released ropes of the white deep inside of Izumi's womb, a loud moan from the hybrid could be heard throughout the center, which startled a few of the animals nearby.

Izumi plopped down onto Toshinori's chest, the two breathing heavily as they recovered from their intense orgasm. Yagi began to rub the cat's back as he slowly began to process what just happened to him.

"To… Toshi…" Izuku murmured, Yagi sitting up a little hearing the nickname.

"...Y-You said my name…" he says softly in shock, considering that only Nemuri only called him that. Did Izumi teach himself how to say it after hearing his coworker say it, or does Izumi secretly know how to read? Despite all of the extensive research everyone's been doing on her within the past few months, there was still so much to discover about Izumi.

"Toshi…more," Izumi says before getting up to switch positions. She had her ass up and head down, ready for her second round already.

"Oh kitty, you wore me out. My body isn't strong-"

"Breed!" Izumi whined before making a small growl at him, the lavender scent going into his nose again.

Sitting up, Toshinori saw his cock rising up despite having such an intense orgasm just a few minutes ago. Was Izumi's scent causing this instant revival or was he that desperate for some action? Either way, he got up on his knees and positioned himself on Izumi's entrance.

"I don't know what you did to me, but I'm just going to let it happen… for science, of course," Toshinori says in defeat before inserting himself back into her with ease thanks to the slick. He thought this time he would take things slowly like how humans do during sex, but his body moved on his own as he began to go at a fast pace, giving Izumi no mercy as he ravaged her needy pussy.

And that's how Toshinori spent the rest of his night. Fucking Izumi in different positions until her body couldn't handle it anymore. Yagi hasn't had this type of sex since his college days and honestly, he loved every second of getting lose and living like it was 1999 again. He couldn't even remember how many rounds he did with Izumi after round two. He just hopes he didn't hurt his kitten in the process.

The sound of Toshinori's alarm on his phone woke him up from his deep sleep. He opened his eyes and felt pain all over his body as he turned off the alarm. Why was he outside, why did his back hurt so much, and who was laying on his chest? His hooking up days were over and he didn't have any interest in dating anyone.

He looked down to see a sleeping Izumi on his chest. Widening his eyes, he realized what he just did.

Holy shit he fucked Izumi last night. So many damn times.

Before he could get up and check for any bleeding or injuries, Toshinori suddenly heard the metal door of the fence open. He turned his head to the side to see Aizawa walking towards him.

Kneeling to his level, Aizawa shook his head as he stared at Yagi with his usual poker face. "Not sure if I should be surprised or not," he simply states.

"Look, I can explain…" Toshinori says in defense, although he wasn't sure Aizawa was going to believe his story of Izumi luring him in with her power scent.

"How the hell do you explain you fucking a catgirl without coming off as a pervert? Just bring her in the office so we can check her out… and maybe check you out too," he says before standing up.

"But I have a reasonable explanation…" Toshinori whined softly before attempting to pull Izumi away from him, but it seems that she was budging. "Wake up Izumi…"

"Sure you do…" Aizawa rolled his eyes before he tried to help Toshinori get the clingy cat off of him, but with his coworker's touch, it must have woken up Izumi. The hybrid hissed at him and tried to scratch him with her sharp claws, but Aizawa backed away in the nick of time.

"God, I'm starting to hate cats now…" he says irritated, before going towards the door. "You handle her, I'll be feeding the rabbits."

"Oh, hey wait! Could you bring me a spare uniform?" Toshinori asked, glad that Izumi was covering up his mostly nude body.

"Why-" Aizawa noticed the ripped up clothes that were near the tree and nodded. "Oh, yeah… sure.." he says before leaving the two alone.

Toshinori sighed and looked back at Izumi who was looking at him curiously. "You're going to be the death of me, you know that?" he tells her, only getting a small meow in response.

After what happened with him and Izumi, Toshinori tries his best to explain to Aizawa what happened to him, which took a lot more convincing to do. The only evidence he had was the lavender smell that lingered on his body even after he took a couple of showers to get it off.

"You'll just have to see it when Izumi gets on her next heat, just keep this between us, okay?" he tells the other, Aizawa hesitantly agreeing.

But surprisingly, Izumi started to give signs of pregnancy within the days that passed. Weight gain, her nipples getting swollen and pinker, vomiting, and being surprisingly affectionate towards the other staff members. For the first time since her discovery, Toshinori's coworkers could get close to Izumi without getting scratched.

Toshinori didn't want to say anything, he was in complete denial of Izumi's pregnancy. They tried injecting human semen in her multiple times and it didn't work! So why would it work this time?

But after the fourth day, Aizawa did a pregnancy test on Izumi and sure enough, she was indeed pregnant. Toshinori finally confessed to everyone about what happened and of course, everyone thought he was sick for having sex with Izumi as they considered her as a wild animal like the other animals. Yagi embarrassingly explained the whole ordeal, Aizawa being a witness of the aftermath. Torino thankfully didn't fire him on the spot and decided to keep him around, but made everyone sign NDAs regarding the situation. It is pretty bad PR if people found out that one of his employees had sex with Izumi on the property.

"We'll just say that you volunteered to donate your sperm cells…" his boss said to him at the meeting, Toshinori praying that people will buy the story.

All of the staff members eventually accepted Toshinori's story, but he noticed people distancing away from him except Yamada, Nemuri, Aizawa, and his boss. It was understandable, he would have done the same thing if he was in their shoes.

The news quickly spread of Izumi's pregnancy once visitors noticed the belly bump and change of behavior. News reporters surrounding the rehabilitation. Many questions were asked and most of them were answered.

Business at the Yuei Wildlife Rehabilitation Center went on as usual, but as the months went by, people around the world were both excited and nervous about how Izumi's babies will turn out.

It was three o'clock in the afternoon, after closing time for the public. giving antibiotics to All Might for the infection he got, he got up and went over to Izumi to check on her. He stopped in his tracks when he saw Izumi whimpering on the ground and holding her large belly. Izumi's in labor!

Entering the pen, Toshinori kneeled to Izumi's side and pet her head to soothe her, which made her purr. "It's going to be okay, Izumi. I'm right here."

"To..shi…" she murmured to him, snuggling into Toshinori's chest. He blushed at the nickname, still in shock that she could say it.

Aizawa, Yamada, and Nemuri passed by and stopped to see the situation. Looking up at Toshinori for any instruction. "She's in labor, I think you should record this and bring any medical equipment just in case.…" he tells them.

It took about ten hours for Izumi to birth to all six of her kittens. Toshinori was tired but he had to stay by her side, as whenever he moved away Izumi would panic and call out for him, which thankfully they got that on tape. The whole labor went by similarly like a normal cat. Izumi will push out a kitten, she will lick off the blood off their fur until they begin to squeak, then she'll wait for the next one to come out as she protected and feed the current kittens. Rinse and repeat.

It was a long journey, but Izumi's pregnancy was a success. Four girls, and two boys. It was a miracle, both for Izumi and for zoology as a whole.

Toshinori gently cleaned up any excess blood on Izumi's tail and lower region, while she fed the babies with her milk. At first, he was unsure how to feel about having Izumi's babies. He wouldn't be able to raise them like human children. He wouldn't be able to watch them play with other children on his block and see them become aspiring adults as he rocked in his rocking chair, old and retired from his successful career.

They were still animals; wild animals that the world was still unsure of their origins.

After tossing the wipe into the bin, Izumi gave Yagi a small meow, probably wanting him to come over to keep her company. He did so without hesitation, shaking off his tiredness. He laid down behind, caressing her fluffy hair as he closed his eyes on the rest of them.

Maybe this wasn't so bad. Toshinori was a workaholic and couldn't see himself retiring anyway anytime soon. Hence why he stopped dating after he got his junior position. Besides his... somewhat involuntary sperm donation, biologists study the children's life cycle and find out more about hybrids as a whole.

Only time will tell.