Many years ago, spring had come around in the Mushroom Kingdom. This meant it was time for old Piranha Plants to wither into the earth, and for new ones to be born. As the Piranha Plants absorbed sunlight, they slowly but surely gained the nutrients needed for reproduction.
When they finished soaking up the rays, they spit out flurries of seeds that flew like dandelions. Adorned with yellow, orange-tipped, vibrant petals, the seeds carried themselves through the air, using their petals as sails. They traveled far and wide throughout the Kingdom, and were able to take root just about anywhere. Carried by the wind, they would ensure another surviving generation of Piranha Plants, but one seed was on its way to something even bigger.
With the fated seed, the winds seemed to go wild, somehow carrying it farther than the others, even into territories unclaimed by the Mushroom Kingdom. It landed in a rocky region, more than distant from any other Piranha Plant, or possibly even from another living being. It rolled into an area soft enough to take root in, and managed to sprout and collect sunlight. Although the area seemed desolate, the sprout was found by strange purple beings, that were not quite Toad, or even of the earth. Though the presence of a growing plant surprised them, they afterward paid it little mind, until they hatched an idea. Using the waste products of various, horrible experiments, the creatures exposed the seedling to dangerous amounts of the waste, which had been very radioactive.
The infantile seedling suffered severe shifts in its D.N.A., but by a gift from fate, it survived the change; in fact, it seemed to have even become stronger as a result. It continued to grow through hailstorms simulated by the violet beings, and it did not succumb to an imposed drought. Eventually, a young plant emerged from the ground, though it had shocked the violet-skinned creatures to see it had not been born a Nipper Plant, but a small, free-roaming Piranha Plant!
More changes from the D.N.A. scrambling had become evident, such as the plant having green lips, despite the fact that all known Piranha Plants had white lips. Also, the growth of what were supposed to be roots had been terribly stunted, resulting in stubby legs that were incapable of taking root like a normal Piranha Plant's, but were just as strong as a root, allowing the bud to walk freely, even carrying its oversized head. Also, the petals found on the seeds often fall off of the Nipper Plants shortly after they emerge, but this plant kept them, though they actually did not hurt its appearance.
Nipper Plants always sprouted in groups, and so the small plant instinctively saw the purple creatures to be its friends (frankly, if the mutated bud had hatched near others, it may have been eaten due to its outstanding differences and the occasional Nipper/Piranha Plant cannibalism). They, however, realized what the little bud could be worth, and subsequently took in the young plant and raised it. It did not take long for them to realize even more unusual traits, such as surprising strength for its age, and a voracious, omnivorous appetite. It had become adept at walking on its disproportionately small legs, though this had to be partially trained. It had almost become something of a pet to the creatures, and they had even reached a consensus on its name, Petey.
At first, Petey was very happy with its keepers, as they played with it and kept it company. They even adorned him with a pair of trousers that were styled to match his polka-dotted head. As he got older, he grew at a great rate, as he had been very small after he sprouted, even smaller than the average Nipper Plant. However, it did not take long for the pet-like ambience to fade, and the purple things had seen Petey only as useful for their own goals. Unlike the maturity rate of standard Piranha Plants, which lasted several months, Petey had taken years to fully mature. As he matured, he was forced to participate in cruel experiments that the purple creatures had been conducting, often rather painful attempts to make up for his faults in mobility and intelligence. Thankfully, he had also been gifted with an impressive regeneration system that not only healed his body, but would also restore his D.N.A. to its 'original' state, should it be altered in some way.
What they had not realized about Petey was his capability of intelligence and comprehension, which was quite higher than they assumed, as they took him to be a relatively brainless creature. He was not content with the fact that his keepers only seemed to value him as a vicious monster who could do nothing more than intimidate and subjugate. He had often been forced to ingest prisoners of the violet creatures, a duty which pained Petey. He did, however, subconsciously develop a taste for the shelled ones, Koopa Troopas, as he had heard them called. Petey could not speak the language of his keepers, but he understood it clearly, and could tell they had no plans for letting Petey decide what he could do with himself, despite his having fully matured. Regardless, Petey felt a sense of loyalty towards them, as they had taken him in and showed him kindness since his birth; he had known no one else in life, and he partially couldn't bring himself to think about rebelling against his caretakers.
Sometime later, long after Petey had become full-grown, he was introduced to the rulers the violet beings. After extensive study, he was deemed to be an impressive specimen, and that he and his keepers would be rewarded. Petey learned that the rulers of his keepers had invaded some nearby Mushroom Kingdom, and that he was invited to a celebration of their conquest. He was to make a special appearance from a large pipe, and that a treat would let him know when he was to appear. He was not told what the treat was, but he simply assumed it to be something edible.
Beneath the ceremony, Petey was guided to his proper place, and he looked down the pipe, awaiting his signal. He watched and saw a figure lowered to the other end, not clear food, but what appeared to be a woman with yellow hair and a pink dress. Petey did not find it to be appetizing, and waited for the actual treat, but he was yelled at by some purple creatures, and reluctantly jumped through the pipe and swallowed the woman. Before he had gone completely down, he noticed two particular individuals, one of red and one of green. Also, before he left, he was given a shiny, blue piece of...something. Though he wasn't told what it was, he was told to ensure no one take it from him, and thus he promptly swallowed it. He was also given a key, but he was not told what it unlocked. This too, was swallowed to ensure it could not be taken from him.
Sometime after, Petey was directed to another meeting, this time to a cave where he would receive another treat. This time, a pink-shelled Koopa Troopa was to be the treat, and Petey was more keen on this treat. As the Koopa was held by a rope, one of the purple beings cut the rope, and she was ingested by Petey. He looked around, and saw that the violet-skinned beings had left the area, and he also saw the red and green individuals again, and had heard them being called the Mario Brothers. He did not know if they were dangerous, but he traveled underground to try and find his keepers in another clearing.
While he was burrowing, his stomach began to hurt, and he figured it had been a result of the 'treat' that he had eaten earlier. He made his way to another clearing, and he promptly regurgitated the woman in the pink dress, and his stomachache had already started to fade. He was glad to know that it was still alive, but he burrowed away before checking if it was able to make its way out. He soon reached another clearing, where he ran into the Mario Brothers.
Before Petey could decide what to do, he found himself attacked by both brothers at once, along with what appeared to be smaller versions of themselves that he had not noticed earlier. He was then given time to attack, and decided that he must fight back. He lunged with a fearsome bite, but it was countered by an attack from a hammer. He was then attacked by the four beings at once, again, and his next attempt at attack was countered. He tried his best to defend himself, but each of his assaults were rendered useless, and each technique used by his four aggressors was more painful than the last. He flew into the air and cried loudly for his keepers, but there was no response. The retreating purple creatures could certainly hear Petey's remarkably loud voice, but they all ignored him and continued on their way, leaving the defenseless plant to fruitlessly try and defend itself.
The pain had been horribly excruciating, Petey had been burned far more than any Piranha Plant would ever wish upon its worst enemy, burning bolts of electricity left awful stings, and he had been bruised and beaten to a nigh-unimaginable extent. Finally having reached his limit, Petey gave a final, pained cry, and collapsed with a huge crash. However, this had not been enough for the Mario Brothers, who continued to attack him, even though he had been literally beaten into unconsciousness. After triggering a nerve, which was located somewhere around Petey's neck, Petey unconsciously regurgutated the pink-shelled Koopa Troopa, the shiny shard, and the key he had been given. The Mario Brothers finally relented on Petey, and eventually left the area with what Petey had regurgitated.
Petey had been savagely beaten, but he had not been killed. Biding his time in the cave, his body slowly healed, thanks to the impressive regenerative system he had been gifted with. Later, when he regained consciousness, he had a gut feeling that his keepers had abandoned him, and he proved himself correct upon noticing that no activity could be heard thoughout the cave, no vibrations of machinery, nor echoes of voices. Not a single purple being ever tried to find him, or even mention or think of doing so.
However, there was one, the one wearing the pink dress happened to come across him as she had been trying to find her way out. Petey was too exhausted and angry to wonder how she happened to come across him, or if she had been unable to climb through his burrowed trails that led out of the cave, and had thus been trapped. Regardless, she felt pity for the clearly injured Petey, despite his earlier action of eating her, and she kept him company for some time. She somehow was able to reveal a large vegetable from underground, even though Petey never came across a single one in all his travels through the cave, and she shared it with him. Petey did not understand English very well, but he understood her sentiments by the tones of her voice. He understood that she had forgiven him, and that her name was Peach. She could then tell that her name aggravated Petey's ravenous hunger, so she pulled out another vegetable for them to share and bid him farewell.
However, the woman's kindness (and food) had rejuvenated Petey, who had already been close to a full recovery. Before she left, Petey summoned the strength to stand up, and he called for her, then opened his mouth wide once he got her attention. She did not understand what he wanted, until Petey gestured inside his mouth and then upwards. She then understood what he wanted, and voluntarily sat inside Petey's mouth. He closed his mouth, and then jumped into the roof of the cave, and burrowed upwards. He thrashed rapidly, making his way upwards, until he eventually found his head above ground. He made himself completely unearthed, and he gently regurgitated Peach.
With a wave, she bid him a thanks, and a goodbye. Petey then rested, and finally took to the air, where he would get his thoughts in order. He remembered his anger at the Mario Brothers for the unfair, cruel fight; and at the purple creatures. He did not know how he knew, but he was certain that they were to blame for his being different, and when the ultimate result of their actions toward him subjected him to unthinkable pain, they had abandoned him and left him to die without a second thought. Petey remembered the kindness he had seen from them, and then their betrayal of it, and he decided he would hunt out his enemies and make them pay for what they had done to him. However, the kindness of the woman, Peach, had stirred something in him, and it even quelled the violence and rage that his thoughts had been building. He resolved to forget his troubled past, as it had brought him to where he was, and it ultimately made him a stronger individual. He flew onwards, searching both for something to soothe his hunger, and towards a brighter future.