Halloween Monstergirl Mashup Part 1 (Kazuma Tg/Tf)

Time has come to rise once again. You mortals would never understand the pleasure of getting rampage again after being forced to stay dormant after such a long time. Ah, but tonight, this Halloween night, I shall stir the pot of the supernatural, and you, dear reader, are my confidant in this wicked revelry.

You see, I am not just any cauldron; I am Enigmauldron, a relic of ancient magic, awakened on this hallowed night when the boundary between the worlds is at its thinnest. The inky darkness of the witching hour cloaks me, and my cast-iron belly stirs with anticipation. It's not every night that a cauldron is allowed to speak, and it's even rarer to address someone like you.

As the moon hangs high in the ebony sky, casting eerie shadows on the earth, I feel the energy of countless souls who once stirred within my depths, each one contributing to my supernatural power. You may think I'm merely a vessel, a tool for brewing potions and spells, but you'd be mistaken. I have witnessed centuries of secrets, and I've been a silent spectator to countless enchanting and terrifying rituals.

Tonight, as I simmer with arcane energies, I invite you to join me on a journey through this night of enchantment. From witches' covens to ghostly haunts, from ghoulish gatherings to faerie frolics, I shall be your guide through the surreal and the uncanny. But beware, dear reader, for the rules of reality bend and blur on this All Hallows' Eve, and you might find yourself ensnared in the very stories I weave.

So, hold tight to the edge of this magical cauldron, for the night is young, and there's a world of wonders and horrors to explore. And as I bubble with anticipation, I promise you an experience unlike any other, filled with the essence of the supernatural and the enigma of Halloween itself.

“Uhm, excuse me sir cauldron?”

What? Can't you see that I am in the middle of something here?

“I hate to interrupt your oh so special speech, but I have been waiting here for a good ten minutes listening to what you went on about, and I still have no idea why I am here. Would you mind enlightening me, oh great cauldron of doom or whatever?”

Imbecil! Who do you think you are to speak to the great Enigmauldron like that.

“I’m Kazuma. Now can I go home?” The foolish boy naively asked, not knowing the fate that would befall him in just a few moments.

“Oh great, now you are even live narrate my words. Exactly what I needed to figure out what that stupid fate is you speak of.”

When the victims are as clueless and impatient as this one, it almost makes you want to plunge them headfirst into their demise without any further information. But alas, I am an honorary cauldron. So I’ll enlighten the fools unfortunate enough to stand before me today.

You, unfortunate victim, have been chosen to become my servant, terrorizing worlds and lands to show them the true meaning of Halloween. There is no way out, no escape, only servitude and monstrous power awaiting you here. All for the completion of my evil plan!

“That's great and all, but how do I get out? I might not have a lot to lose where I came from, but I still would prefer to go back if at all possible.” Kazuma spoke as if he didn’t understand any of my words. Some humans truly are incapable of understanding even the simplest ways to say that there is no escape from me on a day like halloween.

“No, I did understand. I just chose to ignore you.”

…

“Okay, I get it. I don't see a way out of this forest from here. What do I have to do for you to let me leave? Or become your servant or whatever?”

Errhem… The moment you arrived at this place, your soul has already been magically bound to the contents of my being. For now, the liquid is clear and unsoiled, just like a human should be. But now you shall throw ingredients into the pot, to turn you into a monster to be truly feared. And should you refuse to throw anything in, then I shall be the one picking out components! And you don't want me to be the one to decide! Muhahaha!

Eh?

“So how many do I have to throw inside until you are satisfied?” Spoke the boy, having already picked up the first vial filled with a special substance that lied around and having thrown it into me without even reading the label. Then he picked up the second vial.

Aha! So you have chosen to take on aspects of a horse. Quite a fine choice if I do say so myself. Many a halloween riders are feared throughout the land, be that…

“Yeah, yeah.” The boy threw the second thing into his soul stew, hesitating not even for a singular moment. “I was asking how many I need to throw in before… Eh?”

That's when the boy realized his mistake as a tingling feeling overcame his feet. Turning down his gaze was just in time to see his leathered boots rip as his feet expanded, growing hard and round like the hooves of a horse. And on top of that, his skin was slowly smoothing out and turning blue, creeping up his legs as we speak.

“What the heck?!? What are you doing to my legs?!?”

Nothing, my boy. You have done that all to yourself.

It wasn’t a lie, he threw the ingredients into the soul stew. Though as skin crept more up, his legs contorted and bent in ways no human legs should ever bend, making him shout at me once again. “How about instead of narrating this crap you tell me what the hecks happening?!?”

The first component you threw in added a horse component to your body, the second a sea serpent component. Quite the curious mix you will find it to be, but the cauldron is not satisfied. This is far from over, so please insert the next ingredient.

“How does Horse and Sea serpent even work togethaaaaahhh?!?” Just as Kazuma asked another foolish question, the blue tint of his skin reached all the way up his thigh, and seemingly everything exploded at the same time, the boy barely able to catch his breath.

Every time he breathed in, his thighs inflated a bit more beyond human proportions, and when he breathed out, his spine extended both ways, making both his midsection longer and pushing out the other way in the form of a thick serpentine tail. And by the rate he was panting, he was basically pumping mass into his body that soon his lower body was heavier than his entire body was before.

“Ha… Haa… Stop… this…”

Select your next ingredient, or I shall do it for you.

“I… ugh… take this then…?” The guy somehow managed to pick up another vial from the ground and throw it into his soul stew. Naturally from his choice, I had to give a hearty laugh.

Ah yes, the drink of a lovely flower. Anyone who’s soul this mixes into is destined to become slim, no matter how broad they used to be. They are destined to become busty, no matter how flat they used to be. And they are destined to become female no matter how manly they used to be.

“They WHAT?!? Hnn!” But it was already too late, which the boy also realized. His midsection had grown way too large for a single pair over thick horse legs to hold, so he crashed to the ground. Though in the middle of his barrel-like midsection, two additional limbs started to push out, growing in muscle mass and bone structure to become similar to the horse legs he had further behind. And after a few moments, those legs were strong enough to lift his very heavy and blue tinted body up once again.

Although Kazuma was clearly concerned about something else. He was feeling the full blunt of what I had just explained, with his still human half… or rather, his still human portion of his body slowly starting to tint blue as well as his waist pinched in dramatically, giving him a very trim waist. Then the blue color crept up to his chest and there was immediate panic, as the more blue his chest became, the more it pushed outwards, becoming the two glorious mounds he was destined to obtain.

B-cup, C-cup… by now the little thing between his hind legs was also disappearing, giving a sensation assault from all sides.

D-cup… there was no stopping it, no matter how hard he tried. Even his jacket started to change to fit his now more busty frame, just to not rip like the rest of his clothes did.

E-cup and a loud moan was let out by the boy, although saying that he was a boy was simply not accurate anymore. He was clearly a female victim now.

She was dazed, clearly still fighting with the reality of what her body had become. Yet it was clear that something else was spreading through her head. An undying loyalty and drive to obey the Enigmauldron with her entire being.

“Ugh. Sure, tell yourself that, you pot. Are you happy now?”

Not yet. The soul stew still demands…

“Yeah, yeah. This got too weird for me already anyway. How much more do I need to throw in so that you are finally happy with me?”

Listen fool, if you don’t tread carefully I will make you regret…

“Mermaid tail? How does that even work with me having a body like this?”

The fresh girl didn't listen to me one bit, just taking the next vial and throwing it into their stew once again. I was starting to boil, the audacity of this victim is something almost unbearable. Maybe it was even part of the way she changed her soul making her this disrespectful, it was hard to tell.

Facts are two things, anyone who fills their soul with ingredients completely becomes completely loyal to me, the Enigmauldron. And second, having thrown in mermaid components just caused her to grow multiple fins across her body, starting with her horse half with the biggest one and then more down the serpentine tail, becoming smaller as they went along until even her snake tails tip became another fish fin.

Though worst of all, she wasn't paying attention to me in the slightest. Which is when I decided to pay it back to her. I grabbed two very deliberately picked vials and smiled evilly.

Foolish girl, your form shall take a more drastic shift! May you lose your head over it!

“Who announces that they smile evilly…?” And then her head popped off her neck. “Eh?”

The fool flailed her arms around wildly, trying to catch her detached head, yet she didn't manage to catch it. But neither did it hit the ground. The head just started floating in midair, as bluish flames erupted from her neck that was now in full view of her gaze. She definitely stared at herself for a few moments dumbfounded, which was a priceless expression to behold.

But it was not over yet, as she was soon to notice. Her hair quickly started to act up, sprouting from her head like pumpkin vines from the soil, cascading down her disembodied head on either side of it. They quickly bundle up into two long twintails, yet not into ordinary twintails. The tips of his strands started to fuse together, becoming two clumps of masses on either side of her head, before reforming into the form of two additional hands, made purely out of her own hair.

“Woops~ that's convenient~” The monstrous girl spoke, grabbing onto her shoulder with her hair hands to pull her head closer to it. It was still floating in midair, but she now at least had a bit of control over where it floated too.

Tremble in fear as you now embody aspects of the Dullahan, the headless knights destined to fight to eternity and beyond, as they embody death as much as the grim reapers. And the only way for you get ahold of your head shall be with your hair arms, which make you even more monstrous than you were before. Not even your head is spared now.

“Already told you, thank you for the convenience. At least my head doesn't float off into the night now.” She spoke, not at all afraid of her misery for some unexplained reason.

How are…

“Oh cool, I feel like I can leave now. Guess my soul is full with that energy you wanted to pump me full with and I think I now know how to leave this forest. Was a great to meet you though, Mr cauldron.”

Wait… Where are you planning on going?

“Going to nearby villages and scare them a little bit. Using the power given to strike fear into the hearts of innocent people. What? Did you expect me to become a servant of yours for real? You must be joking!”

That's when she turned around while keeping her head locked at me. “Maybe I’ll come visit again once I am done with whatever I am planning. Maybe not. We will see.”

No! I haven’t even told you what my evil plan is! You shall become… and she is gone.

But she just didn't even listen and just started to gallope away, her massive body powerful and unstoppable. Even her tail she dragged behind her fell some trees along the way whenever it crashed into them. And soon she was gone, having disappeared into the forest, leaving only a trail of fallen trees in her wake.

And the entire time I was wondering. What exactly did I do wrong? Because whatever I did do wrong with my power, I should probably fix soon because the second victim was already on its way…

---

Galloping out of the forest comes the first of five monster  girls that this unholy event will bring. Kazuma from Konosuba, a  character that people really wanted to see get transformed, shall be a  four hooved and serpentine headless rider for the time being, ready to  show you the true meaning of halloween.

This is the first of five works from the Halloween Monstergirl Mashup event Hiros53 and 97Tsukishima are hosting. We hope you enjoy~

Changes to Kazuma:

Monster girl species - Centaur, Sea serpent, Dullahan

Additional changes to:
Tail -> (Mermaid fins)
Boobs -> (Beeeeeg Boobs)
? -> (Hair hands to hold her head)