Wendy was deep in contemplation as she walked towards the front gate of the castle, "Hmm, taking out one lowly guard is no problem, but the Mushroom Kingdom has a standing army. Now, it's a pathetic standing army that's never a match for my father, but, then again, my father always brings his own army... Hmm, yep, I'm going to need an army, especially if that meddlesome Mario is at the Castle."
The two Troopas at the front gate saluted and opened the way for their superior, Wendy walked into the desolate courtyard and looked around; Troopas, Goombas, and the occasional Lakitu were running training drills to keep in shape. Wendy thought out loud to herself, "I'm going to need to gather up enough of this rabble to make a proper army." Wendy was interrupted by a loud rumbling in her stomach, "But first I should probably get rid of a little bit of this gas, I don't need these underlings passing out or running away screaming while I'm trying to rally them. Now the question is where to do it?..." Wendy scanned her surroundings once again and noticed a conspicuous red pipe tucked away in a corner of the courtyard. Every few seconds or so a Piranha Plant would pop out of the pipe and chomp fruitlessly at the air a few times before retreating back within.
Wendy rubbed her hands together deviously, "Oh, yes, that's just perfect" she muttered to herself in anticipation. She walked over to the pipe and climbed up to the top, planting herself right on the edge with her ass pointing into the hole. Piranha Plants weren't typically known for their intelligence, with a few noteworthy exceptions, but even they knew better then to attack a Koopaling. Wendy snickered, clenched her fists and began to blow noxious fumes into the pipe, the sound reverberating like a brassy trumpet against its sides.
Wendy sighed in relief, it didn't hurt to keep the gas in, but it did feel good to let it out. Wendy continued farting into the pipe for a solid ten minutes before deciding that she'd purged enough of it from her system to keep her for a while. She looked in and pipe was near full to bursting with vile yellowish-green fumes, so thick she couldn't even see through it down the pipe. "Hahaha! I'll bet that Piranha Plant is a brown, withered up husk after all that! No plant life could withstand that much of my gas!" Wendy took prided in herself, and was getting ready to start climbing down, when all of a sudden the pipe began to shudder and shake, Wendy gripped the sides to keep herself from falling over. Looking back into the pipe, Wendy was shocked to see her gas beginning to drain down the pipe as it continued to shake, and strange gurgling noises could be heard from its depths. Wendy carefully slid down the side of pipe and took several careful steps back, curious at the new development.
After a few more second the pipe stopped shaking and went silent... Then, she was knocked onto her backside in surprise as a Piranha Plant came tearing out of the pipe and flailed wildly in the hot volcanic air. It was presumably the same one that had inhabited the pipe before Wendy got done with it, but one wouldn't have been able to tell by looking at it. For starters, it was larger, much larger, almost three times its original size, it's a wonder that the pipe didn't burst as it forced its body through it. Second, its coloration was completely different, its red base had instead taken on a sickly green, the same color as Wendy's farts, and it's previously white spots had become a shade of pink, the same as Wendy's Bow, it also appeared to have completely lost its trademark teeth. And third, its behavior was quite different.
Rather than snapping at the air, it faced towards Wendy and shut its mouth, a pair of cheek-like indentations formed which rapidly began to expand as if its mouth was filling up with air. It then reeled back and lunged forward, opening its mouth to launch a cloud of fumes at Wendy. Wendy instinctively held her breath to avoid inhaling the unknown gas, but a few inadvertent whiffs revealed to her that it smelled exactly like her gas, as a matter of fact, it was her gas! Somehow, her farting on this unfortunate Piranha Plant had the unintended effect of transforming it into some kind of new strain. Wendy was incredulous, "Wow! I knew that Piranha Plants were resilient and adaptive, but I had no idea something like this could happen. I wonder, can use this in my plans? I mean, to me the gas smells fine, but this demands further testing... Also, this Plant needs a name, well, the closest thing to this is the Putrid Piranhas on Lavalava Island, so I suppose I'll also call this a Putrid Piranha."
Oddly, as Wendy considered all this, the Putrid Piranha did nothing but watch her, as if it was waiting for something, Wendy hardly noticed this however; as she was too busy looking for an unwitting test subject for her new creation. A nearby solitary Koopa Troopa performing warm-up exercises seemed the ideal candidate, Wendy walked up the Troopa and pointed in his direction, "Hey, you!" She shouted. The Koopa Troopa looked around before pointing at his self and replying, "Er, Me?" Wendy rolled her eyes and nodded, "Yes, you, Trooper, Come 'er, I need you for something!" The Troopa looked hesistant but wouldn't refuse a direction order from a Koopaling, "R-right, away, Mrs. Koopa, Ma'am." The Troopa answered and began rigidly marching behind Wendy.
"Oh, will you relax! It's not like I'm asking you to jump off a cliff or anything... You see that Piranha Plant over there?" Wendy pointed to the Plant in question. "You mean that real big, funky looking one? Yeah, I see it. Huh, that's bizarre; I didn't think we had ones like that growing around here..." The Troopa mused. "We don't... Go up next to it," Wendy ordered. The Troopa's eyes went wide, "Er, Ma'am?" "You heard me, Go. Stand. Next to it… That's an order!" Wendy demanded and stomped her foot on the ground for good measure. The Koopa swallowed hard, "Y-yes, Ma'am."
The Troopa and Wendy walked up directly adjacent to the Pipe. The Putrid Piranha seemingly ignored Wendy, but lobbed a cloud of stench at the Troopa, who immediately reacted in much the way one would expect; The Koopa groaned and pinched his nose shut with one of his hands, waving the air with his other hand desperately, his eyes shut as they were beginning to water, "Oh, for the love of King Bowser, that- urk! That smells awful!" The Troopa was so distracted by the gas that he failed to notice the Putrid Piranha lick it's lips, and in less than a moment's time the giant plant swooped down upon the helpless Koopa and swallowed him whole. The Koopa didn't even have time to shout as he disappeared down the Putrid Plant's long stem-like throat.
Wendy was taken aback in shock, "Woah! That... That's not what I thought would happen. Geez, poor Koopa Troopa, I mean, sure, they're cowardly, incompetent halfwits. But they don't deserve that!" Wendy looked away in a rare moment of empathy for the Koopaling... But this moment was short lived as she noticed that once again strange undulating and squelching noise were emerging from the Pipe. A lump reappeared in the Putrid Piranha's throat and began moving up towards its mouth, before finally being spat out onto the ground next to Wendy.
It was a shell, a Koopa Shell, but rather than being green or red, this Koopa shell was a toxic yellowish green, much darker than the already known, but relatively rare Yellow Koopa shell. Notably, the normally white bridge that joined the two halves the shell was a faint pink. The shell rumbled and a Koopa popped out, sporting pale green skin, a pair of shades and a mischievous grin. His skin also seemed to exude the same gas as the Putrid Piranha, that is to say, Wendy's gas, which hung around him like an aura. Wendy was dumbstruck; somehow, the Putrid Piranha must have transformed that hapless Koopa Troopa into this wicked looking soldier.
The Koopa took a knee and bowed his head before Wendy, "Wendy O' Koopa, I am your loyal servant, and I await your orders." He said reverently, though not losing this smirk in the process. Wendy's look of confusion changed to one of understanding and then maniacal glee. Wendy began to laugh hysterically at this new development, and her mind reeled with possibilities. Now this was an army she could use, how would the Mushroom Kingdom's troops fight them when they couldn't even get near them, and she could turn anyone she wished into a loyal servant, or at least she assumed she could... This warranted further testing. "Alright, er... Let's call you a 'Putrid Koopa,' yeah... Go round up every Goomba, Koopa, and Lakitu in the courtyard! I've got an army to build." Wendy commanded as she wrung her hands in anticipation.
"Right away, my Lady." The Koopa responded and rushed to fulfill her orders. Over the course of the next couple of hours, Wendy had her loyal Putrid Piranha create hundreds of Putrid Troopas, Goombas, and Lakitu's. Anyone who hesitated to follow Wendy's orders or tried to make a break for it were apprehended by the converted and forced into the maw of Putrid Piranha. And just like that, Wendy had her her burgeoning... The only question was what to do with it, obviously conquering the Mushroom Kingdom was the end goal, but Wendy wondered if she should use her new army to conquer the Kingdom right away, or use it to capture some of the Kingdom's inhabitants and turn them into her new minions...