Writer's Note:

I don't own the Mario Brothers or Captain Underpants, good day, enjoy the story.

One particular day, Mario and Luigi were down at the local high school, hanging out with superhero Captain Underpants who was undercover as the school principle Mr. Krupp. They hadn't expected anything out of the ordinary, but something odd did happen.

It all got started when a man with strange Einstein-like hair and swirly glasses entered Mr. Krupp's office, here to apply for a job as a teacher at the school. "My name is Professor P." He said in a German accent, "And I am a science teacher."

"A science teacher, eh?" Captain Underpants remarked positively, "Well, we need all the teachers this school can get, Professor P. Eh, is that really your name, Professor P? What does the P stand for, I am quite curious."

"Just leave it be." Professor P said curtly, "I am Professor P and that's it."

"Alright then, you, sir, are hired. Best of luck to you."

After 'Professor P' left the room, Mario raised his eyebrows and scratched his head. As if he could read his mind, Mr. Krupp asked the plumber and Luigi to look into Professor P and ask him for his full name as having someone just named Professor P sounded... odd.

Happy to oblige, Mario pursued Professor P and met up with him down the hall not too far from Krupp's office. "Excuse me." The red Italian said, "But, uh, Professor P? What is your full name, the P has to stand for something."

"Why does everyone want to know what P stands for?" Professor P asked suspiciously.

"Just tell us." Luigi chimed in.

"You better not laugh," Professor P muttered and then said, "My full name is Professor Poopypants." Mario and Luigi raised their eyebrows, "Professor Poopypants? You serious?"

"Its been my name for a while." The professor explained, "People laugh whenever they hear it and..." He snarled through gritted teeth, "Its not funny!"

"Okie dokie." Mario said warily, he and Luigi started to walk away but Professor Poopypants caught on. "And where do we think we're going?" He asked.

"We were just gonna talk with Mr. Krupp." Luigi replied, "Not telling anybody else about your name." The brothers made it back to Krupp's office and told Captain Underpants about Professor Poopypant's name, which got him to put a hand over his mouth as he snickered.

"Its true." Mario insisted, thinking the principle superhero didn't believe him and Luigi, "That's his name, he said so himself. We're not joking, Professor P is not joking. I will admit it is awkward that he would have a name like that, hence why I'm not laughing."

"Well, once the students find out," Captain Underpants said with a slight grin, "They will be laughing their guts out, figuratively might I add. Wait until our friend Professor Poopypants tries to teach his first lesson very soon, it will be quite the scene."

Captain Underpants was right, the very next day, when Professor Poopypants entered the classroom and tried to introduce himself, he was greeted by laughing students... much to his anti-laughter chagrin. "WHY ARE YOU LAUGHING?" He shouted.

"The principle and his pals, the Mario bros, let us know that we have a guy named Professor Poopypants as a teacher here and..." Harold explained as he laughed, "YOU'RE THE GUY THEY'RE TALKING ABOUT! Ha ha ha ha ha ha ha ha ha ha ha ha ha ha!"

"ITS NOT FUNNY!" The professor snarled and started yanking on his hair, stomped like mad, punched a table, kicked a trash can and began ranting about how much he hated being laughed at by the world and that his name wasn't a funny one.

Professor Poopypants tried to educate the students, even bringing up the idea of how to rid the world of laughter at one point, only to keep getting laughed at by all the students. Even the Mario Bros were snickering their heads off after not laughing at his name before.

"YAAAAAAAAAAAHHHHHHHRRRRRRRGH!" After being laughed at for what felt like an hour into his attempted teaching, Professor Poopypants lost his temper and screamed at the top of his lungs, ranting once again about how laughter would not be tolerated by him.

As Mario, Luigi and a seemingly amused Mr. Captain Underpants Krupp watched, the maniac made a run out of the room and down the hallway, screaming with full on rage. Not long after he'd made his way out the door, a rumbling shook the halls.

Heading outside, the two plumbers and the intrepid superhero principle along with all the students watched with astonishment, intrigue and shock as Professor Poopypants approached, piloting a gigantic toilet looking robot with green eyes and stalky arms.

"I'LL MAKE SURE YOU'LL REGRET THE DAY YOU LAUGHED AT PROFESSOR D. POOPYPANTS." The professor bellowed into a megaphone, "AND NO, I WILL NOT TELL YOU WHAT THE 'D' STANDS FOR IN! I WILL NOT BE LAUGHED AT EVER AGAIN!"

Captain Underpants shed his Mr. Krupp persona and went into superhero mode, declaring that he was going to trounce Professor Poopypants with assistance from the super plumbing heroes of Super Mario and his brother Luigi.

Knowing what to do and remembering their previous superhero experiences, the Mario bros and Captain Underpants shared a high five and went for Professor Poopypants, scaling and attacking the giant toilet robot monster head on.

They planted bombs everywhere on the beast as they climbed all the way up to the top of the head, where the mad professor was sitting in his pilot's seat. Mario cracked the window dome with a series of well-placed ground pounds while Luigi used his hammer.

SMASH! With help from Captain Underpants' strength, they seized Professor Poopypants and proceeded to disable his robot, which toppled over and its green eyes closed as green liquid oozed out of the mouth of the beast.

It wasn't long before the cops arrived and the Mario brothers ensured a ranting Professor Poopypants was arrested and dragged off to the police station even as the cops laughed at him when he declared that his name was "Professor Poopypants".

With all said and done, Captain Underpants high fived Mario and Luigi. "Thank you, my friends." He said, "Once again, we have defeated a dastardly deviant seeking to control the world and ruin the peace and freedom of everyone living on this planet."

"All in a day's work when you're fighting alongside the Super Mario Brothers." Luigi said with an optimistic smile and pounded his big brother on the back. "Yeah," Mario agreed, "We're the best of the best in many worlds."

"And I agree." Captain Underpants/Mr. Krupp said with a hearty grin. With that, the three decided to go grab some spaghetti and coffee

The End