Pinkie Pie balanced atop a ladder, reached up to touch the light bulb with a forehoof, and made strange straining noises.
"OOgh! rrrRR! RAARRRRRGGH!"
Twilight walked into the bakery and watched. "Pinkie Pie? Would you like a little help?"
Pinkie Pie sighed. "I guess."
Twilight levitated Pinkie Pie off the ladder and down to the floor, magically unscrewed the burned-out light bulb, and replaced it with a new one.
Pinkie growled, "Hands are the only way I know how to do so many things! Why does my body have to turn into a pony every time I come to visit Equestria?"
"I'm sorry," Twilight said. "But it's really better this way."
***
Thousands of years ago, in a town not far from where Ponyville would someday be founded, strange apelike creatures who stood on two spindly legs walked side by side with normal Equestrian ponies.
"You're the most beautiful sight I've ever seen!" a light green pony crooned as she embraced one of the ape monsters. "I could write songs and epics about you!"
The ape monster said, "Where I come from, no one lets me go on a date with a pony. But here in Equestria, I can be accepted for who I am! And I've found the most adorable fillyfriend in two worlds!" The ape monster knelt in front of her special somepony. "Lyrasgramotter Flutestrings, will you marry me?"
"Yes! Yes yes yes yes yes! And some more yesses!" The green pony knelt to kiss her fiancee.
***
"At first it was really cute," Twilight explained. "Some of the kids were a bit weird...but still cute."
Centaurs ran to and fro across the park. There were one or two creatures who had pony heads and upper torsos on human bottom halves, but they still seemed to do well enough.
Two teenage centaur stallions sat on a very long bench in the sun. "Do you want to go visit Ancient Greece again?" one of them asked.
The other centaur leered. "I wouldn't miss it! Can we do like we did last time? Crash a party, kiss all the girls, and steal all the wine?" He laughed. "With our pony bodies we can run so much faster than humans! They'll never catch us!"
The first centaur looked doubtful. "I don't know. I heard a rumor the Ancient Greeks are trying to invent something they call a spear. It's supposed to be pointy and ouchy."
"Don't be a scaredy chicken!" The second centaur laughed. "We can outrun their spears. Or ARE you a chicken, Phillipides?" He made chicken noises.
The two centaurs sneaked away together that night. They were never seen in Equestria again.
***
"The next generations got even weirder," Twilight said.
***
"What's this?" Celestia asked her assistant Raven Bronzepen. "Next on the schedule...somepony...somecreature...called Oopsie Daisy Halfcentaur?"
Raven pursed her lips. "You've got to see this one. It's a lot easier than trying to explain it to you."
The creature walked in the clumsiest way imaginable, as it slowly entered the throne room. She had a pony torso, one pony hindleg, and one human hindleg. One of her forelegs was a human arm, and the other was a pony leg.
Sticking up about halfway along her pony torso was a human torso. One of the human torso's arms was a human arm, and the other was a Cyldesdale horse leg.
The hybrid creature struggled to the base of Celestia's throne. She tried to kneel, but kept falling over partway through.
"No need to kneel," Celestia's Royal Canterlot voice boomed. "The thought is enough."
"Thank you," the creature said. "As you can see, I am a half-centaur. Although, I'm sad to say, some ponies call me off-centaur."
Celestia listened, expressionless. Over the centuries she'd found that a useful technique.
Raven Bronzepen asked, "Oopsie Daisy Halfcentaur, why have you requested an audience with Princess Celestia?"
"Because I walk funny. And when I try to comb my hair, I keep kicking myself in the head by mistake."
Celestia spoke. "Do you wish me to transform you, so you shall be neither part human nor part pony, but entirely human?"
Daisy's face lit up. "Yes! Oh princess, I would love that so much!"
"Very well," Celestia announced. "It shall cost me a great deal of magical energy and effort. But let it be so!" A bright beam of magic shot from the alicorn's horn, and surrounded Daisy with a glowing cloud.
When the cloud subsided, Daisy was entirely human. Two human hindlegs and two human forelegsarms supported an entirely human torso. From the top of this human torso protruded another human torso. The upper torso had a human left arm and a human right leg.
Daisy looked down at her new body. "Wow!" she said. "I'm amazed. And shocked. And very surprised. I never would have expected this." Carefully moving her upper right human leg, she used the toes to push and pull on some of her human headfur, which had been dangling in front of her eyes. "Thank you, I guess?"
The princess nodded. "You're welcome." She smiled proudly. "Next supplicant, please!"
***
Pinkie Pie frowned. "That DOES sound like a problem. What happened next?"
Twilight Sparkle smiled. "Oh, Celestia got all of the awkward hybrids together, and she cast an enormous spell to fix them all at once. It took three days. When she was done, there were thousands of normal ponies, and a big pool of...WEIRD. Just left over, sitting there. The pool congealed, and we got Discord."
Pinkie said, "Discord? Like our Mister Discord at Canterlot High?"
Twilight pursed her lips. "Does your Mister Discord freeze all the crops for hundreds of miles around, and destroy friendships left and right?"
Pinkie shook her head. "One time, on the last day of school, he turned one of the playing fields into a skating rink. But I don't think he ever destroyed any crops. And I think he'd rather help people MAKE friendships than destroy them."
Twilight nodded. "I'm glad. You have no idea how lucky your world is. Also, maybe now you understand why Celestia and Star Swirl had to cast a spell on the barrier between the worlds, so everycreature becomes the right species for whatever world they go to."
Pinkie sighed. "Couldn't you let humans visit from Canterlot High as humans? Just make a special exception?" Pinkie blushed. "I promise I won't make any babies. Or foals. Whatever you call them. I'll be careful."
Twilight eyed Pinkie suspiciously. "When I was telling you that story...did you understand why my example couple was a human girl and a mare?"
"No. I just thought maybe they were a cute couple. But a girl and another girl can't even--"
"Pinkie, if you don't understand how Equestrian magic lets two mares get each other pregnant...I don't think you should ever visit Equestria for more than three days at a time. Because it takes longer than three days to get pregnant in Equestria, but it doesn't always take MUCH longer."
Pinkie blinked. "Twilight...I didn't think I'd ever meet someone weirder than I am. But are you saying everyone--everypony in Equestria gets pregnant in ways I've never heard of?"
"Yes. That's why we have the three day rule. Because you don't know the first thing about the Equestrian birds and the bees. For somepony like you who doesn't know how these things work, the three day rule is the only way to be safe."
"Okay," Pinkie nodded. "I'll be careful about how long I stay. And if I get into trouble and I get stuck in Equestria for longer than three days somehow, I'll come see you first thing. Or your local version of Nurse Redheart, I guess, if you're not available."
"That's good!" Twilight said. "Now that you know it takes longer than three full days for a mare to get another mare pregnant..."
Pinkie's big blue eyes stared innocently at Twilight.
"Two mares can have a lot of fun in..." Twilight glanced at her fetlockwatch. "Two and a half days. Until you're due to go back." The unicorn princess wrapped one foreleg around Pinkie's shoulders. "A LOT of fun. I've read some books about it."
Pinkie chewed on a bit of her floofy mane as she contemplated. "No. Thank you."
Twilight pulled her foreleg back. "I'm sorry, Pinkie. I didn't mean to--"
Pinkie said, "Oh, I'm honored! Really I am! I haven't had a beautiful alien princess flirt with me like this since...at least last Thursday. But...you're not really my type, Twilight."
Twilight blushed and looked down. "I understand. But I wonder...who IS your type? Maybe I can introduce you to somecre--someone."
Behind Twilight, the bakery's front door opened again, ringing a bell.
Pinkie squealed, "Hi, Moondancer!" Pinkie ran to hug the pony with the big clunky glasses and the nerdy hairstyle that today included a twist-tie to keep her mane from falling forward into her eyes. "It's so good to see you again!" Pinkie nuzzled her.
"I'm so happy to see you too," Moondancer said.
Twilight looked incredulous. "You've GOT to be KIDDING me! Not your type? Moondancer and I are the SAME TYPE!"
Pinkie said, "You're a good friend, Princess Twilight. But Moondancer and you are NOT the same type at all."
"How's that?"
Pinkie put a foreleg around Moondancer's withers. "You know I'm a big party pony. Moondancer is the most sensitive party pony I know. Parties mean SO MUCH to her."
Twilight sputtered. "I suppose...I mean--"
Pinkie gave the newly arrived unicorn a lascivious look. "And look at those big, sexy eyebrows. They say the bigger the eyebrows...well, I shouldn't talk about that where little foals might hear."
Twilight sputtered wordlessly.
"And such fair, delicate skin. I don't have a THING for redheads exactly...well, maybe I kind of do. But don't worry, Twi, I'm sure a LOT of girls like ponies who are so very purple. And are pretty magic princesses!"
Twilight shouted, "Well, she and I are both huge nerds! And our faces and body shapes and manestyles are basically the same! It's like one of us is a copy of the other, just recolored! And I could get a pair of glasses and wear them all the time, and put tape on them too! So there!"
Pinkie shook her head sadly. "Moondancer's hairstyle is completely different from yours."
Twilight yelled, "Mrs. Cake! Give me a piece of wire or a rubber band or something!" Too impatient to wait for Mrs. Cake to come out of the back room, Twilight ran behind the counter and rummaged around for something she could use to give herself a nerdier manestyle. "Look! I found something!" Twilight levitated a pretzel and ran around the counter. The neurotic unicorn watched her own reflection in the counter's glass front, while she tried to trap as much of her mane as she could in the pretzel's loops.
"Awww, Twilight! That thing with the pretzel is really cute! Even though I could never leave Moondancer for you, I'm sure you'll find somepony who'll make you very happy. Just not me." Pinkie turned to Moondancer. "Let's skip this joint. We've got almost two and a half days left, so let's make them count." Pinkie led Moondancer out of the bakery.
Twilight sighed. "Won't I ever find anypony who can love me? Anycreature at all?"
Spike popped up from behind a table. "Twilight? Isn't there some spell you could use, to make yourself look just like--"
"Yes!" Twilight shouted. "That's the answer!" She ran out of the bakery.
"--Rarity?" Spike finished his sentence. "Oh, never mind." He waved to Mrs. Cake, who had just appeared behind the counter. "Barkeep? I'd like to drown my sorrows in cake."