Harry Potter & The Mixed Up Day

It was the first day of fifth year. Harry was on the Hogwarts Express with Ron and Hermione, all awaiting the new year. Except Harry. He has a secret that no one knows about. He is really Dudley in disguise, and he doesn't want to pretend to be a wizard. Neither Harry nor Dudley knew why the odd switch has happened, but both did know it wasn't a good thing.
Meanwhile, while everyone else was riding across Britain on the train, Draco Malfoy woke up in his new house. He moved in to the Chamber of Secrets over the summer, since Harry killed the basilisk. His twin goes to classes and lives with his parents most of the time unless he actually feels like it. If that happens he forces his twin into the chamber and goes about like nothing is unusual. He decided that he wanted to go to the Opening Feast so he hid in the entrance Hall to ambush his twin.
Soon everyone, including the real Draco, arrived at the Opening Feast. Everyone was looking forward to the interesting things that might happen, but no one was expecting what all happened next. As everyone was eating billions of frogs appear in the Great Hall, covering every surface and eating everyone's food. This was very annoying, but no one cared too much. As Hermione pulled out her wand to banish the frogs, they started biting everyone. All attempts to stop them completely failed. The teachers couldn't explain what was happening, they just wanted the frogs to leave like all the students did.
Well, almost all the students, that is. While the other kids were screaming or trying to get away, Neville was talking to the frogs and calling them names like Aunt Gertie and Uncle Bob. When everyone around him edged away, Neville tried to explain that they're his relatives, but that just adds to their suspicions that he's insane.
Suddenly, every suit of armor in the castle walked into the Great Hall. All of them take off their helmets at the same time and everyone gasped. They were all students who had been hiding in them to avoid classes. Even though they'd been in the armor for years they'd all suddenly gotten claustrophobic and afraid of the dark and decided to come out.
Once the teachers got over the shock of the armor, they turned to the Gryffindor table and noticed a large circle around Neville. Professor McGonagall and Professor Flitwick came over to see what's going on.
"He thinks the frogs are his relatives," said Parvati.
"He's talking to them!" George exclaimed.
"Come with us, Neville," Professor McGonagall said sternly.
"But... but where are you taking me?" Neville asked.
"Down to the 5th house."
"The 5th house?"
"Yes, the special house. Now come with us now."
"But...no! I'm not insane! They're really my relatives. Honest. Please, just listen to me."
"You're coming. Let's go."
Meanwhile, 'Harry', Ron, and Hermione were sitting at the other end of the table watching everything. "I wonder if he's telling the truth?" Hermione asked.
"I don't know," said 'Harry', figuring he should at least say something so he didn't get discovered
"I bet he is," Ron suddenly exclaimed. "And I know what I'll do about it. I'll just bribe the school to let him stay in normal classes."
Hermione looked at 'Harry' with an odd expression. Dudley was sure that Harry would know why she was looking at him like that, but he had no clue. Fortunately, he was saved from having to comment when she spoke. "Uh, Ron," she started, "you don't exactly have enough money to do that..."
"Oops," Ron suddenly said, cutting her off and looking extremely flustered. "I just gave away our secret. Well, you guys are my friends. I guess I can trust you. My family is actually filthy rich. The poor thing's just a cover story."
"A cover for what?" Hermione asked, but before Ron could answer, two rather ditzy, blonde 3rd year girls wearing miniskirts suddenly ran over.
"Hermione!" the one girl squealed. "We didn't know you were, like, a witch!"
"Yeah!" the other girl exclaimed just as enthusiastically. "Too bad they, like, don't have cheerleaders for Quidditch."
"Huh," Ron interrupted. "Cheerleaders?"
"Duh," the 1st girl says. "I mean, Hermione was, like, the best Head Cheerleader our school has ever had."
"Head Cheerleader?" Ron snorted. Hermione was about to defend herself, but before she could say a word the oddest thing yet happened.
The doors of the Great Hall opened, and a camera crew came in following Hagrid. Except Hagrid was slowly changing. Pretty soon he had become none other than Jerry Springer, who had somehow discovered the wizarding world and decided to market to them in addition to his Muggle show. Jerry and the camera crew walked up to Crabbe and Goyle.
"And here we have two 40-year-old wizards who are pretending to be less than half their age. Not only that but they're also Death Eaters!"
Dumbledore stood up and shouted over all the resulting (and existing) confusion, hoping to settle everything down. "Everyone go up to your common rooms immediately!"
When the Gryffindors arrived at their common room everyone decided to have a huge chess tournament. No one really knew why, they all just had this strange urge. Everyone who owned a wizard chess set brought it out and play started. Soon, however, a problem has been detected. No one could tell who's directing which pieces, since everyone was talking at once. The frustrated chess pieces went on strike and started rioting and attacking everyone with a lot of force for one inch tall pieces of ivory.
On top of all the chaos of the chess pieces, the salamander Fred and George blew up a few years ago crawled out of the fireplace and turned into a dragon, which took over Fred's mind. His body instantly disappeared. Fred tried to keep the dragon in control, well as controlled as Fred liked, but the dragon's instincts were beginning to take over.
Everyone noticed this and ran out of the common room down to the entrance hall. They tried to get back in the Great Hall but couldn't. The house elves were striking too! It seemed like they finally listened to what Hermione had been saying. They summoned the striking wizard chess pieces and the dragon from the common room, who had been trying to escape anyway, to aid in their protest. They also made millions of chickens and turkeys appear, who joined the frogs and strikers in invading the school.
Everyone had enough with the insanity and ran out screaming to the grounds but they all stopped suddenly. Directly in the students' path, a colony of ladybugs started turning into Blast-Ended Skrewts! Apparently, they were just ladybugs gone wrong the whole time.
Dumbledore ran out from the castle and turned all the skrewts back into ladybugs. Just as everyone thought stuff might be getting back to normal, Dumbledore turned into Crookshanks and ran out the school gate. He took the Hogwarts Express back to London, and traveled to 4 Privet Drive.
Meanwhile at the Dursleys', Harry, who was still in Dudley's body, got incredibly hungry because of his great size and ate Mr. Dursley. Just then Crookshanks arrived, turned back into Dumbledore and proposed to Mrs. Dursley. He then saw Aunt Marge, who he met last year at the lake because she is the queen of the merpeople. However, before either one can say a thing, Dumbledore suddenly realized that he forgot something important and Apparated back to Hogwarts. Never mind that he could've just done that in the first place.
While this was all taking place in the Muggle world, at Hogwarts the real Hagrid came and got rid of Jerry and the camera crew, the frogs, chickens, and turkeys, the house elves and chess pieces and turned the dragon back into Fred. Then Madame Maxime walked in the door. Hagrid walked up to her and said, "Hi, Mommy!" Then he realized what he had just done and quickly ran away, pulling Madame Maxime with him before anyone could try to figure out what was going on. The Slytherin table tried to figure out, but all of their guesses were a bit, um, nasty, shall we say.
Before the Slytherins could corrupt the minds of everyone in the school, Dumbledore came back and told everyone to go back into the Great Hall. He started everybody singing the school song, because the song and the accompanying ribbon are really hypnotism mechanisms to make sure all the students think Voldemort is evil, although many of the Slytherins and some other people have managed to escape its control.
Then Dumbledore suddenly decided that he didn't want Filch to be at Hogwarts anymore. Filch was really a Muggle who stumbled upon Hogwarts and the magical world so Dumbledore made him be caretaker and never let him out of Hogwarts. But Dumbledore decided that he was just too mean and gave him a Memory Charm and made him leave. The students all rejoiced at this and started setting off sparks and screaming. But Snape gave everyone near him a detention cleaning up his entire storeroom, so the students quickly settled down.
Meanwhile, Neville escaped from the 5th house and got to the Gryffindor table. He somehow realized that all the important people are really someone else. So he tried to become 'Harry' but the magic involved was very advanced. Since he has almost no talent in Transfiguration, he just ended up turning into a duck. This was still a pretty big accomplishment for him, but he didn't want to be a duck for the rest of his life. After failing at turning himself back to normal, he waddled over to Hermione.
"Quack!" he quacked loudly.
"Hi, little duck," Hermione said sweetly. "Where did you come from?"
"Quack, quack, quack!" Neville quacked more urgently.
"Oh, are you trying to talk to me? Well, I suppose I could try to learn Duckish, but I warn you, it might be awhile."
Neville realized that all he could do was quack, and therefore no one could understand him. With a resentful quack, he waddled slowly out of the Hall, in search of someone who spoke Duckish to turn him back to normal.
Draco, who knew everything that was going on, decided that all of this was very stupid and went back to the Chamber of Secrets to sleep. He knew it was quite a brilliant plan to wreck havoc on Hogwarts, but he wished Marcus Flint could've made it a bit more interesting, or at least deadlier. Just as his twin was about to leave the chamber the !Evil Hand! came and ate both of them. Well, at least it was deadlier now. Draco perched on a cloud over the Great Hall, an unseen ghost, and planned to wreck havoc on all Mudbloods. But just as he finished planning, he heard his favorite target make a startling revelation that completely ruined his plans.
"Harry, Ron, there's something I have to tell you. I'm not really a Muggle-born."
"What!" Ron exclaimed. 'Harry' realized that he should probably say something, but didn't really know what she was talking about so lay there silent. He fidgeted when he noticed Ron looking at him strangely. Luckily, Ron was too curious about Hermione's startling statement to think about it to much.
"Yes, it's true," she continued. "The people who raised me aren't really my parents. They're just evil dentists who kidnapped me to test their tooth experiments."
"So who are your parents then?" Ron asked. 'Harry' was still sitting there, trying vainly to understand what the hell she was talking about.
"Well, I don't know who my mother is. But my daddy is really Voldemort."
Ron jumped up yelling.
"Ssh, Ron. He's not really evil, just...confused. Can you blame him?"
Ron quieted down a bit, but eyed her suspiciously for a while. 'Harry' excused himself to go the bathroom, since he still didn't get anything that was going on around him. As he left, Hermione turned back to Ron, and began speaking before Ron could stop her.
"There's something else I need to tell you, Ron. I only went to the ball with Krum to see how you would react. I wanted to see if you would get jealous. Since I guess you did, I need to ask you something. Ron, will you go out with me?" She said this all in one large breath.
Ron stopped to think for a moment, then realized, Voldemort-fathered or not, he really loved her and couldn't refuse. "Sure, Hermione, of course I'll go out with you."
Just as the words came out of his mouth, Krum appeared. Hermione might not have liked Krum, but he still liked her. He turned evil with jealousy, killed Ron, then promptly disappeared again.
Everyone around them just stared with shock, including Draco, who had forgotten all about his evil scheme. However, they were quickly distracted.
Dumbledore, Professor McGonagall and Professor Flitwick had disappeared during the middle of this conversation, although few people noticed, they were too busy listening. They appeared again, and the results were quite comical. Dumbledore had gotten a nose job and dyed his hair pink. McGonagall fell in love with Flitwick so she dyed her hair blonde and let it down, since he liked it better that way. As soon as they got into the Hall, both of them ran away again and get married.
Professor Snape, confused by all of this, decided to also to something strange, and actually washed his hair. But the water did something to his brain, so he switched houses and became the Head of Gryffindor in place of McGonagall, who didn't seem to be coming back.
Dudley, sitting in the bathroom, somehow figured out that there was a way to switch them back. He forgot it immediately afterward, but didn't care; since he was finally back to normal. He was glad because now he can start eating everything in sight again, not to mention that Hogwarts was just too strange. Dudley realized that his dad was dead, but really didn't care since he's such an evil jerk. Or maybe because spending that much time in Harry's body rubbed off on him a bit. Whatever the cause, he accepted living with Dumbledore and his mother quite happily.
Suddenly Harry woke up in his cupboard and realized that the entire day was just one big, very confusing dream.

The fic has now ended