Several months ago, at the week of the Animalian Outbreak...
Even though summer was sending and school was starting, the zoo was still a popular place to go to. The Lyre Zoo wasn't nearly as big as some of the other zoos in the United States like San Diego or Cincinnati, but it contained a healthy amount of different animal species from around the world.
For instance, there was the resident polar bear at the zoo, Chilly. Chilly had been raised in captivity, but even so, he was a prime specimen of a bear, being 9 feet long, four feet tall at the shoulder and a healthy 900 pounds. The polar bear enclosure might have seemed a little cramped to some, but Chilly had a big pool that he could swim in all the time. And he had this place all to himself. It did make the bear a little lonely, which was probably why he bonded easier with zookeepers and one particular girl.
Marcy went to the zoo almost every day. Most girls would have spent their free time hanging out with her peers, but Marcy didn't quite have anyone she could call a peer. Marcy was very smart for her age. At 9 years old, she had already been moved up several classes. This was the start of her freshman year, but Marcy wasn't quite as excited as she should have been. In 8th grade, she already stood out a lot, or she would have if the other girls weren't so much taller than her. While Marcy did have a lot of brains and was mature for her age, her body wasn't anything like that. She was extremely aware that her body hadn't even started puberty yet and now she would be a school with classmates who were near the end of puberty. It was hardly a surprise that Marcy soon acquired the nickname 'Mousy Marcy', though Marcy's hair was a very pale blonde instead of mousy brown. The only time that girls seemed to show any interest in besides from teasing is to use her smarts with their homework.
Well, all girls weren't like that. There were some girls who seemed nice. Like Abby Brown and her friends. They had tried to encourage Marcy to join their little group, but Marcy was just too shy and distrustful to try and bond with them. And now Sarah had been turned into a horse woman. Marcy had heard some kind of virus has caused a bunch of animals to become humanoid and apparently Sarah had gotten it from her horse. Marcy felt a bit of envy. She wished she could have a big body to match her big brain instead of being trapped in a kid's body with a practically adult mind.
That was probably why she felt such a connection with Chilly. As the only polar bear at the zoo and a gentle nature that contrasted his huge body, he probably felt as lonely as Marcy. Interestingly, it seemed the connection went both ways. Chilly always perked up with Marcy was there and spent as much time looking at her as he did ambling and swimming around his enclosure. The zookeepers thought the relationship between girl and bear was pretty cute. They even let Marcy near Chilly, though they did need to watch her. After all, polar bears are the largest land carnivores and leaving a little girl alone with a bear even as gentle as Chilly was begging for disaster.
The day that everything changed started completely without warning. Marcy was sitting in Chilly's enclosure, watching the white bear swim around in his pool. Of course, she wasn't just in there by herself. There were two zookeepers that were cleaning up the enclosure. But soon, one of them got a call on his walkie-talkie about a disturbance over at the big cat enclosures and had to leave. Pretty soon, the other one got a call about something going over at the giraffe enclosure. There wasn't time to call for someone else to watch Marcy, so she was told to just stay back and not go near Chilly. What none of them realized was that the Animalia Virus, which had gotten into the water system, was now starting to pump through the zoo's pipes. Across the zoo, more animals were starting to become exposed and uplifted. And that included the water being pumped into Chilly's pool.
Marcy first noticed something was wrong when Chilly didn't seem to be swimming as smoothly as before. It looked like the bear had become completely exhausted and was starting to struggle with staying above the water. "Chilly, you need to get out of the water!" called Marcy. Almost as if Chilly could understand her, he started heading back to the edge of the pool. However, he seemed to be having trouble getting a grip on the edge and kept slipping back under the water. Despite being told to stay back, Marcy couldn't help but rush to the edge of the pool. "C'mon, Chilly, you need to try harder to get out," she said. As if her words gave him encouragement, Chilly heaved himself out of the water, letting out a low roar that also spat out a lot of water, a good amount of it splashing Marcy and even getting into her mouth.
As Chilly crawled onto land, Marcy started to notice there was something different about him. It seemed like his muscles were moving under his skin, pulsing and shifting. That would certainly explain why he was having trouble swimming. As she watched, Chilly's massive torso seemed to be gaining a completely different kind of definition, his barrel shape flattening out. His front legs seemed to stretching and slimming, though not by a wide margin. His hind legs were also changing a lot, Chilly couldn't even lift them up as were changing too much. His legs extended a lot as his hips made loud cracks as they altered so he could spend all of his time on his hind legs. His bear behind compacted down a lot, gaining a more defined shape. To her embarrassment, Marcy started to notice that Chilly's backside now resembled a human butt.
It was probably fortunate at that point that she had started to notice her own change by then. She had thought the heat was caused by her worry for Chilly, but she soon noticed white fur was started to appear on her skin. It didn't take long for her to notice the black claws that were extending from her fingertips or the ones slice through her shoes. The growth of her tail didn't garner much attention as it was a stumpy little tail. But Marcy could hardly ignore it when her face started extending. Her nose pulled out further as the tip of it turned black, her mouth joining it at the end of the signature elongated muzzle of a polar bear. Her ears had already moved up to the top of her head.
Marcy felt her face all over in disbelief. "What happened to me?" she asked.
"You're beautiful." Marcy looked down to see Chilly had flipped over onto his back. The polar bear looked a lot different from before. His barrel chest had flattened out into an impressive set of pecs and abs and his arms and legs were of humanoid build, though no less muscular. His face had somewhat compress, giving him a fuller range of expression.
"Did you just talk?" asked Marcy, trying to wrap her head around this whole thing.
"Yes, and I meant it when I said you're beautiful," said Chilly, "And I don't mean just now. I remember you telling me about those other girls, the ones who tease you for being too small. They don't realize that it's not just your brains that make you special. You have such a kind spirit that people overlook just because you seem young. I've wanted to tell you that you had true inner beauty for so long, before I even knew exactly what that meant."
Overcome with emotion, Marcy didn't know what to think. No one ever saw her as anything more than a big brain in a little body. At that moment, it didn't matter to her that those words were coming from a bear who had become part human or that she was a bear herself. She leaned down and gave Chilly a kiss on the lips, something their muzzles were capable of doing. Chilly was more than a little surprised, he gave a small gasp that allowed Marcy brief access into his mouth.
Marcy pulled back, suddenly feeling embarrassed. "Sorry, I guess I got a little overly emotional," she said, "It's just...just..." She trailed off as she started to feel warm again, this time it wasn't caused by more fur growth. She soon started to feel a tightness over her body. She looked down and saw that her clothes seemed to be shrinking on her. She quickly realized that it was in fact the opposite: her body was growing.
"Marcy, are you alright?" asked Chilly with concern as he stood up. His body length translated to his new two-legged height, making him a towering 9-foot titan. And yet, his relative tallness was becoming less apparent to Marcy as she was getting taller herself.
"I'm fine," said Marcy, did her voice sound different? "It's just that my clothes are getting too small on me," she grunted as she tried to claw off her restricting clothes. Chilly extended the claws on his new hands and helped Marcy. Between the two of them, they soon ripped her clothes to shreds. Marcy was thankful her new fur coat was more than thick enough to cover her up.
Marcy continued to grow in height, taking on more mass. It wasn't long before she felt a tingling in her chest. She looked down and noticed that her chest was started to bulge a bit. Her now-black nipples, previously hidden with her fur, were starting to stick out, much more than they had before. Marcy put her hands over her nipples and felt the mounds that were building up underneath of them. It didn't take a high IQ like hers to realize what was happening now. "I'm not just growing bigger," she said, her voice definitely different now, "I'm growing up."
Chilly watched with fascination as the little girl who he had bonded to was growing before her eyes. Puberty was hitting her fast and hard. Her indistinct mounds had rounded out into full globes that were inflating rapidly. Her hips were expanding out to the side as her rear started to plump up in proportion to her new breasts. As her limbs extended, Marcy noticed that they were thickening up with strong muscles. Her shoulders also expanded to accommodate a more muscular build as her stomach, set above a relatively small waist, rippled and hardened with strong abdominal muscles. Marcy let out small moans as she grew in mass and age, her voice becoming deeper and huskier.
Finally, the transformation came to an end. Instead of a small girl who had been skipped ahead a few grades, Marcy was now a large polar bear woman. But her bulk wasn't fat. Well, her large breasts and ass were definitely well-rounded, but that was the only parts of her that were soft. Her body's muscles were now heavily-defined, though not grossly so. She had the build of a sexy amazonian bodybuilder, even if she was covered in white fur. The only part of her that was identifiable as her old self was her page-cut pale blonde hair and her blue eyes, which went very well with her new arctic appearance.
"I didn't think you could get more beautiful," said Chilly with amazement. It was mind-boggling that the girl he had like had just transformed into an extremely attractive bear woman.
Marcy looked up at Chilly with a smile. While she had gained a lot of height, she had stopped growing at 7 feet 8 inches, which still gave Chilly over a foot over her. "Well, you did help bring out my inner beauty," she said, her new voice deep and melodious. From her higher vantage point, she could now take in more of Chilly's sculpted physique. She hadn't much time to admire how handsome he was before, but as she took him in, he caused more of a stir within her loins. She knew what was going on, her parents having already explained to her what her classmates' puberty ultimately led to. She could feel her body heating up as she felt her new mating instincts kick in. "And I think I should properly thank you," she said in a sultry tone before kissing him, pressing her body against him as she did so.
Chilly was quick to respond to her flirting. It had been too long since the zoo had brought him a female to breed with. He wrapped his strong arms around her and kissed her back. His libido was quickly building up, thanks in part to the virus. It wasn't long before he could feel his cock start to harden, his sheath grinding against Marcy. He broke away from the kiss and said, "Let's take this to a more private place. We don't want any visitors looking in on us."
Marcy nodded in agreement and they both walked to the back of the enclosure, out of sight of anyone who'd be looking in. Marcy laid down and spread out her legs, her moist pussy visible through the fur. Chilly allowed his cock to fully emerge, which was now a very impressive length. He gave Marcy a few sample licks, his long tongue able to reach pretty far into her pussy. Marcy gave low moans at that, but that was not enough to quench her fire. Chilly slowly climbed over her, his shadow covering her almost completely. He lined up his cock carefully before he slowly buried it into her. Marcy let out a louder moan at that as Chilly filled her up. As soon as he was safely settled in, Chilly started to thrust into his new mate. Marcy grunted as she felt this new pleasure. She reached up and fondled her breasts for more stimulation. She was a bit surprised to feel milk coming out, but she didn't really care. She was too caught up in the mating.
The two bears started moving faster as their pleasure grew. They let out grunts and growls that didn't sound very dissimilar from ordinary bears. Their movement caused Marcy's breasts to bounce quite a bit, enticing Chilly to thrust harder. Eventually, the peak had been hit and they both let out a roar as Marcy clenched and Chilly blew his load deep into her. They panted very deeply as they started to cool down. Marcy probably should have felt some shock about becoming a polar bear sow and mating with Chilly this quickly. But it didn't really bother her. She always was pretty mature for her age and her body matched her mind. Well, she didn't expect to be this big and muscular, but it wasn't something she was going to object about. The other students will have a lot harder time bullying 'Mousy Marcy' now.