A Pokemon trainer discovers a discarded cape and gets a surprise when trying it on. Commission for randompersonindeed on Discord.
=======================================================================

Rob, like everyone, heard about the legends of Lake Verity. That it was supposedly involved in the creation of the world, and that a legendary Pokémon resides in the cave at the middle of the lake. He set out on his own despite friends offering to help and others discouraging him from going in the first place. He fills his bag both with food for himself, extra Pokéballs and treats for his Pokémon. He left a written note on his door stating that he had gone to Lake Verity and set off.

The road to Lake Verity on his own was hard, encountering many wild Pokémon and having to take regular breaks to heal or rest. Eventually, despite all the hardships he faced, he makes it to the lake. It is very calm and peaceful when he arrives, and nobody else is around. There’s even fewer wild Pokémon than there was on the routes leading up to the lake. Rob walks up to the shore of the lake and sits down, takes off his shoes and rests his feet in the lake, thinking about the best way to get to the cave in the middle.

While relaxing, he reaches over to get some food out of his bag and notices something in the grass. It’s a dark blue fabric. He gets up and checks it out, picking it up. It looks like a cape of some kind. Odd to find something like that here, but maybe someone accidentally left it here. He takes it back with him to where he was sitting and puts it in his bag, intending to take it somewhere later in hopes it makes it way back to its owner. He goes back to thinking about the cave in the middle, if only any of his Pokémon knew how to use surf. Or if he could swim that far of a distance. He decides to try swimming anyways, changing into his swimwear and diving into the lake. He manages to make it twenty feet or so before he realizes he can’t go any further and swims back, defeated.

He sits back down on the edge of the lake and dries off, then changes back into his regular clothes. Before long, though, he starts thinking about that cape again. He wonders how it would look on him, not that he plans to keep it or anything, but he figures it wouldn’t hurt to try it on before he turns it in to a lost-and-found.

He unzips his backpack and takes the cape out, standing up. It certainly looks like it would fit him, the neck loop looks big enough. He undoes the clasp on the cape and throws it over his back, then closes the clasp around his neck. He turns around a couple of times, the cape flourishing in the wind, as he looks over himself. Satisfied, he goes to take it off but finds it difficult to undo the clasp. He looks down and notices something weird with his hands, they look light blue and seem to be covered with something soft. As he takes a closer look at his hands, he notices his fingers moving closer together and no matter how hard he tries, he can’t pull them apart. He keeps trying but eventually his fingers begin to fuse together and form two flippers on the end of his arms. He feels his hands and realizes that they’re covered in some sort of soft, downy type of feathers.

Rob panics and tries to frantically dig into his backpack to find anything to help, but he can’t get it open. As he keeps trying, his arms grow wider and flatter, looking more and more like a penguin’s flippers. The light blue down spreads up his arms and over his shoulders, sweeping across his abdomen. Two white spots appear on his chest, though this isn’t seen under his shirt, and goes down to his legs. The cape he is wearing seems to stick to him more and becomes covered with darker blue feathers. Rob tries to pull it off, but it feels impossible to do so. At the bottom of the cape, grow two nubs that grow long and flat, almost looking like a tail. As the feathers crawl down his legs, they grow shorter and shorter, making his pants feel loose and pooling on the ground.

Rob kicks his feet to get his pants off and finds his feet turning yellow and toes merging together. Soon, his feet only have three digits on them. Even though his legs have stopped shrinking, he feels his shirt and hat get looser on his body, and the world around him seems to grow. The tall grass is looking even taller. Rob shuffles his shirt off and shakes his head to throw his cap off and looks down at himself. His torso starts expanding, looking rounder in shape, but not fat. The cape he’s wearing seems to have shrunk to fit him, though, and begins to fuse with his exposed back. Two lapel-shaped growths come out of the neck of the cape and partially cover the white spots on his chest.

Rob looks down at himself, his hands, now flippers, and his feet and tail. “I-I’m…becoming a Piplup!” The realization finally hits him, and he starts running, abandoning his belongings. He hopes that if he can make it somewhere before he fully transforms, he won’t be mistaken for a wild Piplup. However, he doesn’t get far before he trips and falls. As he gets up, dark blue feathers cover the back and sides of his head up to just above his eyes. “Nononono…this can’t be happening!” He gets up and tries again, only to fall again. White feathers cover the area around his eyes and a bit of lighter blue feathers grow in above his mouth to meet the darker blue feathers. His hair falls out, then his mouth hardens and turns yellow. It pushes forward and rounds out to form a small beak. His eyes turn blue and round out to form tall ovals.

Rob looks over himself again, and realizes he’s not made it very far. “Piplup!” He exclaims, then looks surprised at what he said. He tried to call out for help, but all that came out was Piplup. “Pip! Piplup!” He tries again but finds he can only say ‘Piplup’. He worries more now, on the outside he’s indistinguishable from a wild Pokémon. What if he gets caught? What would happen to his own Pokémon? He becomes more determined and walks slowly but steadily, still falling occasionally but getting more used to it. It feels like walking through a massive jungle now being just over a foot tall. What was only a hundred feet or so of tall grass feels like miles when you’re this small.

After walking for what felt like hours, Rob hears a sound, it sounds like someone talking. Maybe they could help! Forgetting that he can’t speak English anymore, he confidently runs up to the source of the voice, popping out of the tall grass where a different Pokémon trainer is. He tries to explain what happened. “Piplup! Pip, Piplup!” He exclaims excitedly, but then stops when he remembers that he can’t talk. The trainer looks down at him and smiles, and throws out a Pokéball, and a Luxio comes out. Rob looks up at the big cat in fear, knowing that he’s weak to electric types. The trainer shouts some commands, which Rob cannot understand and the Luxio fires off a spark of electricity towards Rob, which strikes him dead-on. Rob falls over and gets a tingling feeling all over his body and finds that he cannot get up. He quickly realizes that he’s been paralyzed!

Rob fights to try to get up but he just can’t move no matter how hard he tries. The trainer reaches into his bag and pulls out another Pokéball and throws it right at Rob. The ball bounces off Rob and lands in the grass, then pops open. A red beam of energy flies out of the ball towards Rob and quickly engulfs him, pulling him inside. As Rob is pulled towards the ball, he feels himself becoming lighter as his body is converted into light energy and pulled back into the Pokéball. Rob isn’t sure what to do, but he tries to move any way he can while inside the ball. He struggles, bouncing around inside but just cannot manage to resist. Soon, a click is heard, sealing him inside the Pokéball. Hearing this, he knows he’s been caught. He can’t do anything else; he belongs to this random trainer now.

All he can think about is his own Pokémon. What would happen to them? What about his friends and family? They’d never be able to find him! The trainer moves on, heading for the lake. He finds a set of clothes, a bag and a handful of Pokéball sitting by the lake. “That’s odd…did someone dive into the lake?” He looks around and finds no signs of anyone. He calls out a few times and gets no response. The trainer decides to just gather up the things and take them back with him, maybe he could find the proper owner later.

Time passes differently while inside a Pokéball. One has no sense of what’s going on outside, so it’s hard to tell how long one has been inside. While pondering everything, Rob suddenly feels a strange energy wash over him. It passes fairly quickly, and by the end of it he feels reinvigorated. Like he did before the fight with that Luxio. After another indeterminate amount of time, he feels a pulling sensation, like something is pulling him out of the ball. He starts feeling heavier as the light energy recombines into organic mass, and soon he finds himself inside of a pen, along with several other Pokémon and the trainer that caught him. Among the Pokémon he was released next to are his own. He sighs in relief, at least they’re going to be taken care of now. He looks around the pen and finds his clothing piled in the corner along with his bag. He quickly walks over to it, falling down a couple of times, and stands on top of the pile. He starts flapping his flippers and jumping and shouting. “Piplup! Piplup!”, trying desperately to get the trainer’s attention. He soon does, but the trainer just comes over and looks at Rob confused. He says a few words that Rob doesn’t understand and then just pats him on the head.

This angers Rob further, and he starts squawking angrily. The trainer is further confused, and he calls out for someone. An older man comes out to the pen with the trainer and looks at Rob, examining him. The older man tries to pat Rob too, which he responds to by biting the older man. The older man grumbles and heads back inside, leaving the trainer alone with the grumpy Rob. The trainer sighs and takes out a sitrus berry and offers it to Rob. Rob, still being upset, refuses, and just turns his back to the trainer. The trainer keeps trying, and eventually Rob gives in and takes the berry. He admits to himself the berry does taste good, but he’s still upset about the whole ordeal, so he just lays down on top of his clothes. The trainer shrugs and leaves the pen, hoping to be more successful another day.

The next few weeks pass by with Rob slowly growing to accept his fate as this random trainer’s Pokémon, and after a month he finally realizes that he won’t be going back so he might as well make the best of it. He starts cooperating with the trainer and soon becomes a formidable Pokémon. Before long he evolves into a Prinplup and learns all new moves. He quickly becomes the trainer’s favorite Pokémon and helps carry the trainer throughout the different gyms across Sinnoh.