It started with a dream. A dream that left Katsuki painfully hard, his dick straining to escape his sweatpants.

He was drenched, confused, but more than anything, he was pissed.

What right did that shitty, little Deku have to intrude into his dreams and present him with a more compelling fantasy than he could have imagined on his own.

Green eyes, bright with yearning, staring up at him from the floor. Green, tousled fur, ears perky and flopping, as he panted excitedly, hanging onto his Katsuki's every word.

His tail was wagging. And god, was this on another level.

This dreamscape-conjured Deku was a dog.

His dog.

Deku turned, deep chest pressed to the hardwood floor, his fluffy doggie ass raised, presenting a cute, pink hole.

Dream Katsuki had his fingers spreading the hole wide, making his dog whine pathetically.

And in that moment, he needed it. He needed it more than anything. It made him feel disgusting, like skum, or worse.

What kindof sicko wanted to fuck a dog? A big dog, a dog that was Deku, but still a dog.

It didn't matter. He needed to feel Deku's fur between his fingers. He needed to hear him panting and keening and whining. He needed to pry open that tiny hole and fuck him into the ground and collar him.

Keep him as a pet.

Perhaps there was a way to forever silence that pathetic mumbling.

And in the depths of his bedroom, with his hand wrapped tightly around his dick, that became his goal.

Several times a week the same dream plagued him, teasing him with Doggy Deku's cute innocent face. His thick tongue running over his cock, cold wet nose poking curiously at Katsuki's balls and taint before venturing back even further.

He nosed at his ass insistently, his sneaky tongue lapping eagerly, quickening his pace before it slipped inside. Deku washed his walls, leaving him shaking and he didn't get tired.

He just. Kept. Going.

Each dream solidified his need.

And so his research began. As did his relationship with Deku.

The boy had always been obsessed with him, hanging onto his every word like a christian to the damn gospel.

It was night and day, the moment he began to make Deku feel safe. This touch starved boy was instantly addicted to the safety that only his Kacchan could provide.

He crumbled easily under Katsuki's expectations, how to dress, when to speak, what to eat.

Within a few months, Deku was falling asleep with Katsuki's cock in his mouth, breathing into the small shock of blond at the base. Fucker had an oral fixation to rival a toddler's.

By the third month, and having no leads on how to make his dream come true, Katsuki began searching the deeper, darker parts of the web, looking for a quirk that could help Deku achieve his true purpose.

It was late on a Thursday when Katsuki found what he was looking for.

Naturally, he was absent from class the next day, having accompanied his parents to Tokyo for a photo shoot. Anything to get himself closer to who he needed to speak to.

He rarely volunteered for such things but his parents would always give him the rest of the day to dick around once the shoot was done.

Katsuki took the train to Shinjuku Station, his destination in a seedier part of the ward.

He traveled the thin allies, the smell of the city was stronger here. Telephone lines and various wires crosshatched above him until he found the small sign that read "The Den" propped next to an unassuming door.

He pushed the door open and instantly a cloying, colorful smoke drifted out, heavy enough to sink to the ground and spread like water, swirling around his feet as he entered.

It was a small, dimly lit place dubbed Madam's Boutique and Bestiary. A woman with shining, true-black hair lay sprawled on a blood-red couch, content as a cat, her slit pupils settling on Katsuki with intrigue. She didn't move though her eyelids fluttered and something in her lap moved.

Her body was draped with loose, sheer fabric and it hid nothing, not even the snake coiling between her legs, its scales wet with milky fluid.

His eyes were glued to where it disappeared into her, burying itself within her folds. The thing must have been massive; he could see its body moving under the skin of her abdomen. It wasn't until she mewled and extended a hand to him that he looked away.

A small dog was down by her feet, licking her toes, her ankles, its eyes closed as it worked.

His heart thundered in his chest. Because of his research, he knew what they were. What they had been.

But this had been done by choice he assumed. Would she agree to his desires knowing only one party would be informed?

"From the swell in your pants, I gather you're not here by mistake, are you, pet," she crooned. She reached down, pulled the snake from within her and draped it across her shoulders, her own slick moistening her skin as it made itself comfortable.

"No. But I don't wan-" He began but she cut him off.

"You are not interested in becoming?"

"No, it's for someone else."

"And yet they are not with you."

"He doesn't know."

She quirked an eyebrow and sat up, taking him in with a slow, sweeping gaze. "And you wish to keep it that way." She concluded.

He didn't reply.

Was he really doing this?

She mirrored his silence for a time, so long he almost turned and left, before she finally named her price.

He could hardly swallow the number, but he nodded, no doubt looking pale.

"Dreams come with a price, my pet." She lifted herself from the couch and moved silently across the room where a filing cabinet sat against the wall. From within she pulled a small packet of paper and a pen. "Specifications are very important. Species, breed, duration, before you bring him, make sure to read everything thoroughly."

"It's not permanent?" He asked, somewhat distraught.

"It can be. However, my willingness varies based on the value of the citizen-"

"He's quirkless," he blurted, hoping this summed up Deku's value to society.

"I see. For someone such as this, permanence would not be an issue. However, make sure to weigh this decision heavily, since it's being made for someone else."

And with that, he left, the form folded and tucked into his jacket pocket.

That night, he filled it out, researching breeds and reading the warnings. It turned out that, once changed, Deku's brain would slowly become simpler, modeled around how Katsuki raised him. And wasnt that just the best part?

At first, Deku would be upset, but a kennel, a leash and the nerds undying loyalty and trust would be enough to convince him to stay.

Perhaps he could say it was an accident.

That he didn't know what happened.

That Deku had simply disappeared…

The woman had said the beginning would be the hardest part. Breaking him down. Comforting him as his dreams slipped away.

A part of him hurt for Deku, but the larger part, the part he nurtured, bathed in the power of becoming Deku's new dream.

Becoming his everything.

The next two years went by in a blur. When he wasn't studying or interning for a hero agency, he was interning with his parents. And when he wasn't with them, he was with Deku.

Molding him, grooming him, and by his third year of highschool, Katsuki was prepared.

Now it was a matter of getting Deku with him to Tokyo. And into Madam Beast's Den.