Ditto

Ditto was sitting by a bush, munching on berries, minding its own business. The Rawst berries were good and ripe, and if somebody didn't eat them soon, they'd go bad. Not wanting to see that happen, it felt obliged to take care of the situation before it became a problem.

As a Pokemon, it wasn't much to look at. A Ditto was a soft pink glob with small eyes and a slit for a mouth. It wasn't bothered by appearances, though. So long as nobody bothered it, it wouldn't bother nobody.

But somebody decided that it was a bother. A small purple Rattata leapt in front of Ditto. "Scram, stranger! This is my bush!"

"Eek!" Ditto swept up a cloud of dust. While it was thus covered, it molded itself into an exact replica of the Rattata. "Leave me be."

Blinking, the Rattata got on his hind legs. "Huh? You a cousin or something?"

"Yes, I'm just visiting. Sorry for the bother."

"Oh. Well that's fine." He furrowed his eyes, lacking eyebrows to perform the motion. "But I thought you were some weird globby thing."

"No, no. Your eyes must be playing tricks on you. I'm just an ordinary Pokemon."

"Okay. Well, enjoy the berries." He nipped a few off himself and ran back to his burrow.

Once the Rattata was gone, Ditto transformed back. If it stayed as the rodent, it might attract predators. It continued eating until full, then set off to find a hiding spot to sleep.

It was able to travel alongside the human-made road for some time, remaining hidden in the tall grass. But when Ditto spotted an ideal hiding place, it was across the road. Not wanting to draw attention to itself, it decided to turn back into the Rattata. Now, what color had it been? Yellow? Yeah, that seemed right, a greenish-yellow. Ditto transformed into a yellow Rattata and ran across the road.

A high-pitched squeal stopped him dead in his tracks. A human girl was jumping up and down while clapping her hands. "Omigosh, omigosh, a shiny Rattata! It's sooo much cuter than other Rattatas! And shinys are so rare, wowza! I'm gonna catch it and it's gonna be MINE! Go Wartortle!"

Her Wartortle, which had been hiding in her shell since the shrieking began, emerged reluctantly. "Okay, okay," she muttered. "Keep the noise down, would ya?" She fired a round of fast water balls at Ditto.

Panicking, Ditto launched an attack. Any attack, just so long as it got rid of them. It fired a similar round of fire balls at the Wartortle, unfortunately to little effect.

"I've never seen a Rattata use Ember before," a boy with them said meekly.

"That just means she's more special! You're mine!" She threw a Pokeball at Ditto, then ran over to pick it up.

"Um, you're supposed to wait just in case they break loose."

"I don't have to. Okay, let's have you out so I can show you off right away!" She pressed the release button.

The shock of being captured had transformed Ditto back. It was a confused glob now. "What's going on?" it asked.

"What?" the girl screamed, causing everyone to wince. "You're not a shiny Rattata."

"No, just a regular old Ditto," her companion said.

"You shut up!" She yanked the ball apart, causing it to disintegrate. "Get out of my sight!"

"Thank you," Ditto said wearily, moving off to its hiding spot. It really needed a good sleep now.

…

Ruby/Sapphire entry: Ditto rearranges its cell structure to transform itself into other shapes. However, if it tries to transform itself into something by relying on its memory, this Pokemon manages to get details wrong.

That girl was inspired by Carmalita Splats of a Series of Unfortunate Events…