Archive of Our Own ^beta

Chapter Text

Chapter 01. 

Halloween was said to be the night when everything supernatural, everything creepy, and things that crawl come out to play. It is the time of the year when goblins, ghouls, vampires, ghosts, and werewolves come out and howl, shriek, and roar to the moon.

Of course, no one knew just how true that was, even more so given the rise in supernatural energies, which caused the barrier between worlds to fracture and crack, letting certain things slip through. Halloween stretches far beyond, reaching past planets, galaxies, different dimensions, timelines, and more. 

During this time, things slip through these cracks. These things are eggs, eggs the size of a Hummer tire. But these were no normal eggs. These eggs contained beings known as Symbiotes, and every Halloween, the symbiote eggs are sent into different dimensions in search of a host, a host to help them grow, to help them get bigger and stronger.

This year, a portal had opened not above ground, but below! To a place long forgotten and buried deep…deep Underground. 

~Scene Break~

Asgore Dreemur loved and hated this day, for it was the night of All Hallows Eve, a night for monsters to celebrate, dance, party, and partake in all manner of sweet treats and foods. The younger monsters would play games, and they would have fun with one another, as the adults themselves had their own parties and celebrations. But for the King of the Mountain, it was just a reminder of how alone he was, his wife having left him due to his issuing of the decree to hunt humans who entered the Underground, his children having died long before he had made his decree. He recalled the days when the Dreemur family would celebrate this holiday and would go out to have fun with their friends. 

But now, he had no one, and that left him with little desire to go and partake in the festivities. Even when Undyne had tried to get him to go with her and Alphys to Mettaton’s costume party. He decided to stay in the castle and simply reminisce about the days before things went wrong. He was inside the castle, simply looking over the containers holding the six human souls, their colors illuminating the room.

“Hmm.” Hummed the king looking over the seven containers as he. “Wait.” Asgore backtracked and came to a stop as he looked at the containers. He saw the soul of Bravery, the soul of Justice, the soul of Kindness, the soul of Patience, the soul of Integrity, and the soul of Perseverance. “So then what is this?” Inside a seventh container meant for the seventh and last human soul, was not a human soul, but instead, there was what looked to be an egg. 

It was a pitch black egg about the size of what Asgore knew to be an Ostrich egg that he’d seen in a few books about human animals. “Where did this come from?” He stepped over the container and lifted the lid to remove the lid-

CRACK

Pausing in his movements, Asgore found that the egg was cracking. “Hatching?” The cracks spread across the egg in a spider-web pattern, and soon the top of the egg shattered, the pieces dissolving away. From within the egg, some sort of liquid as black as the night bubbled and churned before erupting from it were liquid tendrils writhing and wriggling around like snakes slithering through the air, and seemed to turn to look at the king. “Um…hello?”

The tentacles lunged, and in a flash, Asgore found his armor and clothes stripped from his person and was left butt-booey naked!

Despite the years that had gone by, being a monster meant he was immortal, and as such, he didn’t age and had done much to keep himself in good shape. Asgore had a bulky, beefy figure with golden-blonde hair on his arms, legs, chest, and belly. Despite his age, he is very fit with a large set of pecs, each with pink nipples, a bulky, muscular belly, thick, beefy arms, legs, and thick thighs, a bulbous bubble-like booty, and his 15-inch lon,g two-liter pop bottle thick cock was erect, and his honeycomb size balls had grown heavy and swollen from years of neglect and hung low.

The tentacles wrapped around his body, holding his wrist apart and spreading his legs. “W-Wait! Stop this!” Asgore attempted to call upon his magic, to summon his trident or even a burst of fire. And yet his magic didn’t respond; the tentacles moved, descending upon his body, two tendrils moving towards Asgore’s chest and curling around his pecs, another one moved to wound around his waist and even through his fur. Asgore felt the chill of the tentacle's touch.

“W-Wait! Please stop!” He thrashed about, trying to move his arms, his legs, anything to try and escape and get free from the tendrils holding him, as he could only watch as it slowly spread across his skin. The inky black liquid slithered and squirmed over his body, working its way up from his legs and farther up, when it reached his cock and balls, that’s when it changed. The tendrils unwrapped from his legs and then coiled around his cock, encasing his limp member in a cocoon of blackness, and as soon as it was wrapped up, it started pulsating and vibrating around his cock. “Ooooooh!”

Asgore’s mismatched eyes went wide from the sudden vibrations, the feeling of the tendrils pulsing and pleasing his cock, making him roll his hips both to try and get away and to get more pleasure from the tendrils. They weren’t done, as more tendrils wound themselves around his arms and slithered down them, covering them in the same inky blackness that covered his arms. It moved down to his chest, branching out like tree limbs, draping over his shoulders and moving down his back.

“What is happening?” He wanted to cry out, be it for help or for more, he wasn’t sure, but all that was spilling out were heated moans and lustful pants. The tendrils from the top and bottom portions of his body mingled as they formed around his wobbling, booty cheeks. The tendrils moved, branching out to cup both cheeks and giving them a slight smack, making his ass jiggle and shake. “Ooooh! A-Aaaah! S-Stooooop!” And yet the tentacles didn’t stop. 

SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK

The tentacles continued spanking him; they could sense that the king was enjoying the attention and the affection he was getting from them. The mix of pleasure and pain was driving the great king mad; his mouth was hanging open, and a small trail of drool dribbled down his chin. Another set that had previously wrapped around his pecs began playing with his nipples. They pulled, yanked, and twisted the erect buds, enjoying how the smallest things were rewarded by a choked-out moan from the king.

His cock was being tortured, as inside to cocoon of tendrils it felt as if his cock was being licked by multiple tongues, all of them sliding down the hardened member as his lips parted and a cry of pleasure escaped them, a cry which got louder as he felt a thicker tendril slip between his ass cheeks and started to rub and grind against it. Another Tendril splitting off to tease and play with his pink anal star, Asgore was struggling to remain in control as he let out sounds that were caught between gasp, panting, and mewling moans of rapture.

SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK SMACK

“Aaah! Gyaaaa!” Asgore sank deeper and deeper into the ocean of pleasure that threatened to consume him. More and more of the liquid continued to cover his body, caressing every inch of flesh as it gradually covered almost every inch of his body save for his head. And then, right at the height of his pleasure, when he felt the tendril that had been playing with his hole suddenly thrust into his ass, making him arch his back and cry out into the open air, his face was engulfed, and his vision went black.

Cocooned within the massive black sphere, Asgore was in total darkness. He couldn’t see anything, not a thing, but whereas he was blinded, he could very well feel and feel he did. The inside of the cocoon was hot, a pleasurable heat that had the former boy wonder withering and whining from within. “Aaaaah! Nyaaaaa~! Ssssstop! D-Don't stop!” Tiny jolts of what could only be described as electricity buzzed through his body, every nerve felt like they were lit a fire with pure pleasure as the teen's cock twitched and throbbed. 

Meanwhile, the tendril inside of Asgore's ass began to swell, growing thicker and longer, stretching the King from the inside, pulsing and vibrating against his inner walls, sending waves of euphoria through his entire system and straight to his pulsating, throbbing cock, which was oozing pre, only to have it licked up by the tendrils. He never noticed how a single tentacle emerged from behind his head. The tentacles moved, sliding around his head and moving under his ear, and the moment it did, it thrust directly into his head, causing Asgore to let out a sharp gasp. 

The tentacle burrowed deep, moving directly towards his brain, where it attached itself and began spreading out. “Give in.” Whispered a voice directly into his brain. “Give in, surrender, and become one with the hive. Become one with usssss.” Part of Asgore wanted to fight back, to break free of the hold that this slime had on him and escape…but what would be the point? 

“Give in, join the hive, become one with the hive, let the hive love you.” He didn’t have much to go back to; his family was gone, his wife had left him, and his kids were dead. For so long, he had done his best to try and keep his kingdom happy, to keep them hopeful…and yet where was his happiness, where was his love and affection? “Give in, submit, let the hive love you, let the hive care for you.” He wanted love, he wanted affection…he wanted pleasure. 

“Let the hive give you your deepest desire. Join. Usssssss!” That was all it took. Asgore felt some part of him break, and he came. He couldn’t resist; he couldn’t fight it any longer. It was all too much, too much pleasure, too much stimulation; it was overwhelming him. He couldn’t stop himself.

“Yaaaaaaah! Gaaaaaaaa!” He gave in, he screamed, eyes glazed as Asgore had finally fallen and given into the carnal rapture that was taking him over. He squealed as the tendril attacked his sweet spot once more, and what little remained of Asgore’s resolve shattered to pieces.

Cum erupted from his cock, shooting in thick streams that painted the top of the cocoon with some splattering down all over his stomach, chest, and face. Lost in his pleasure high, Asgore was left defenseless as the tendrils seemed to collect his cum and absorbed it. Had he been in his right mind, he would have sworn he heard a voice coming from the cocoon. “Ourssss. ”

Outside the cocoon, six tendrils emerged and grasped hold of the containers that held the six human souls and shattered the containers, and pulled the souls inside the cocoon. For a moment, it was still, and then it gave off a dim multicolored glow as something began to emerge from within; blackness had begun to compress. As something began to form from it, first a pair of legs with clawed feet, followed by a body, then arms and legs, and lastly the rest of it.

It was Asgore, only he was different. Asgore’s body was covered in smooth, black, leathery skin; not only that, but he had grown! Asgore was now a powerful goliath who was exuding dark might from simply his piercing stare. He had strong, bulky muscles that only looked menacingly attractive with large broad, swollen pectorals with glowing blue nipples, bulging biceps, rock-hard abs, muscular thighs and calves, a set of large fat round bubble butt cheeks that would look like they could crush a man’s head if he sat on them, but they’d die happy, and a gargantuan glowing blue 32-inch long 23- inch thick member with a set of huge glowing blue balls beneath them. He had black claws on his hands and feet, and bright blue spikes jutted out of his elbows and knees. At the center of his chest was a glowing symbol looking like the rune symbol seen as a symbol of the prophecy that released a set of small rainbow energy wings. His blonde mane and beard became pitch black, while his face, ears, and horns turned a neon blue. His sclera turned black, making his limpid blue eyes all the more intimidating.

“So…So Gooood!” Asgore's intimidating face twisted into a grin of pure euphoric bliss, his hands cupped his pecs, and he pinched and played with his nipples. At the same time, a tentacle emerged from his body and grasped his cock, and started pumping it as he played with his pecs. Inside his ass, a copy of his own cock was moving, fucking his fat ass while he moved to sit back on a throne his newly attained power had created. “More! More! I-I must have more! I need more!” He begged while throwing his legs up as the cock shaped tentacle fucked him on his throne. 

“And more you shall have.” Purred the voice of the hive, as slowly as Asgore’s new god like power helped create more of the symbiotic slime that emerged and spread across the floor of the room, gradually crawling outwards and spreading to the rest of the room, veins of multicolored energy pulsating through them. “More shall join the hive, you shall be pleased, you shall be loved. And the hive will spread, grow, and breed more!” 

Chapter Text

Chapter 02. 

Doggo had no idea why he was wandering through the castle when it was All Hallows Eve; he should be partying with everyone else, having fun, and enjoying some tasty treats. But the captain had told him she didn’t want Asgore to be left all alone; it was no secret that this day was the same day that they had lost their children, and the Queen had abandoned them, and while people had been prepared not to celebrate, the King told them to enjoy the holiday for what it was and that was remembering those who had long since passed on and fallen. Even so, that didn’t mean their king needed to spend it locked away inside the castle all by his lonesome. 

It also had to do with the fact that all the guards, Doggo, were the only ones outside of Captain Undyne who could get the king to open up about his issues and problems. Making him the fourth person to be considered the king’s closest confidant. So he’d left the party and ventured into the castle to find the king to invite him to come and join in the fun. “My king? King Asgore? Are you there?” And yet, he couldn’t find the king in the library where he would spend the majority of his time, so he made his way to the throne room, wondering if he was tending to his flowers. 

“My king? Are you here, Captain Undyne wanted me to…” Doggo’s words got caught in his throat as he came to a stop inside the throne room. The good news, he found the king, the bad news…he seemed to have stumbled across the king in a rather…intimate moment of self-pleasure.

“Oooooh!” King Asgore was naked, Doggo getting an eyeful of the man’s sexy body. Hands grabbed at his pecs -oh, how often Doggo had secretly wanted to play with those tits- fingers pinched, pulled, yanked, and twisted the erect buds to their limits before letting go and letting them snap back just to continue playing with them. 

The king was rising and falling, his thick thighs tensing while those glorious, sweet and soft mounds that made up his fat ass rippled and shook as the king was bouncing up and down, rising just high enough for Doggo to see the king was riding a toy, a very long, very thick, red colored toy that looked almost like a canine cock! From the brief glimpses that Doggo could see, the toy was glistening, wet with some sort of secretion that helped the king move, his body constantly in motion as he glided up and down along the canine phallic toy. 

Doggo hasn’t been expecting this; he’s been expecting to come find the king held up in the library, reading or remembering his past. He didn’t think he’d find him doing this! 

“Oooh!” Asgore bucked his hips, body rising and falling, his golden hair matted with sweat, and his orange and blue eyes were glossy, gleaming with desire. “M-more! N-need more!” His thick thighs were flexing as the royal monster rode the toy, and while Doggo couldn’t see it, he could hear the sound of the king’s royal posterior clapping as he slammed himself down, doing what he could to try and take the-!

“POP!” 

“Ooooooh!” Asgore’s head fell back as he successfully took the fist-sized knot inside his ass. His mouth fell open in a daze as his cock erupted, a fountain of thick white royal sploogie arched high into the air and rained back down all over the ground, and some splashing back all over the king. Of course, so powerful was the climax that it managed to reach the doorway where Doggo stood mouth open, right in time for a blast of cum straight to the face: burning up his nose, flooding his mouth, and leaving him gasping for breath as he ended up swallowing the mouthful of Asgore’s semen. 

The moment he swallowed, Doggo’s body throbbed and pulsated, causing him to lurch and drop to his knees. His pants suddenly felt incredibly tight, too tight, unbearably tight. ‘Too much! Too much!’ They were so tight it hurt. He fiddled with his pants, forgetting where he was for a moment, all he could focus on was getting his dick free!

He managed to get the first button off right as his pants could no longer contain his raging erection, and his button popped off, and his pants ripped open. Doggo’s cock broke free, popping out of his sheath with a wet “splurge” as it stood proud and tall. Doggo had a canine-like member, bouncing around in the air, radiating musk and sweat. Doggo’s dick was big, really big; his knot was even soft, a solid fistful. His cock was a bright cherry red, swollen out thicker in the tip was mottled purple, around the dimple along the sloping tip, and it bulged out and spread into a smooth circle, pushing out a glimmering bead of precome. The entire thing was about an astonishing 29-inch-long, 9 ½-inches thick pillar of man meat. 

His hands found his thick doghood, and he started jerking it right then and there. ‘God! I didn’t think I was this backed up!’ His balls twitched, spilling out of his pants, the pear-sized furry sack dropped down, nearly dragging him further to the floor, as he felt his balls twitch and churn as a thick plume of watery pre splurged from the tip. ‘I-i need to cum, no, I need to fuck something! But what! There isn’t anything around here that I can fuck!’ 

‘The king.” A voice as soft as satin whispered in his ears. “Fuck. The. King. Look at him, he’s sitting there riding that toy, look how horned up he isssss, he’s asking for it!’ 

The voice did hold some truth….the king was asking for it, he’d changed position. Asgore had spread his legs, leaning forward with his back to Doggo, giving him a full view of those glorious mounds that wobbled and rippled each time he dropped down on the toy, a loud wet “Pop” occasionally coming from his hole. 

‘B-but he’s the king! I-I can’t just…’ 

‘But you can, he’s so lonely, so needy! Look at that ass! Look how he’s riding a toy for pleasure when he could be riding you.’ Whispered the voice, enticing Doggo’s desires to get him to come closer to Asgore, never realizing that from behind him, a mound of darkness had risen, tentacles slowly slithering across his body, clothes being dissolved and melted away, showing off Doggo’s furry, lean, muscular figure and mocha skin. He has broad shoulders with nicely developed arms and biceps, a somewhat wide chest with dusty nipples and a thin waist, a faint six-pack set of abs, strong thighs and calves, and a nicely toned butt. 

‘You are his guard; it is your duty to serve the king and right now.’ So caught up in watching the king, Doggo never noticed how a single tentacle slithered its way into his ears and snakes to his brain, connecting right to it and spreading more tendrils across the monster's mind. ‘He needs you to breed him. He needs you to mount him. He needs you to fuck him.’ Something about what was said tickled something in his brain. ‘Breed Him. Mount Him. Fuck Him. Breed Him. Mount Him. Fuck Him. Breed Him. Mount Him. Fuck Him. Breed Him. Mount Him. Fuck Him.’ 

“Breed Him. Mount Him. Fuck Him.” Doggo began repeating, not realizing he was standing up, as he didn’t notice how his pear-sized balls suddenly surged, churning and growing even bigger than before. “Breed Him. Mount Him. Fuck Him. Breed Him. Mount Him. Fuck Him. Breed Him. Mount Him. Fuck Him.” He mumbled slowly, lumbering into the room, approaching Asgore, who seemed to have finally taken notice of him. 

“A-Ah, Doggo.” As he turned, Asgore’s form shimmered, and rather than the normal form, it was the new form he’d taken upon being converted into the hive. “You’ve come, and you came here to tend to your king.” The “toy” inside of Asgore’s ass unraveled, becoming a mass of tendrils that began to pull themselves from his ass. Asgore smiled, rolling over onto his back, a sea of tendrils unfurled underneath him, pulling the King’s legs apart, exposing his plump, fat ass and his hole. “Come and please your king.”

“My King!” Doggo leapt towards Asgore, his dick aimed right at his hole, and in a single thrust, he sheathed himself inside the tight sphincter that now hugged his penis. Doggo sank into Asgore’s asshole. The moment he was inside of him, his hips jerked back, and then he forced his dick back into him. He moaned, eyes rolling back in his head, and he couldn’t stop himself from moving. His muscular legs flexed as his balls swung back and forth, clapping against Asgore’s cheeks as he moaned, hands reaching up to interlock his fingers with Asgore, who reached up to grasp his hand, and the other moved to make him look into Asgore’s eyes. 

“You’re such a good boy, Doggo.” Asgore purred, praising him while he scratched him under his chin, getting the canine monster to moan, his tail wagging fiercely, and his movements were getting faster, shoving his dick as deep as it could. “You’re making me feel so good, don't you see?” Their interlocked hands moved to be placed on Asgore’s stomach, where Doggo could feel the tip of his penis through the wall of flesh and muscle.

“Hmmm, by the ancients, you're so deep in me, you are pleasing US so well!” Doggo missed how the mass of tendrils was swaying and swirling around them, gradually enclosing them, more of them climbing along his body, covering every last inch of his body in tentacles. “You wanted this, didn’t you? You want to fuck me?” 

“B-Breed you.” Doggo groaned, tongue hanging out of his mouth as he pulled out of him, his dick spasmed, twitching and spilling a heaping helping of doggy pre into his insides. When he pulled out, there was a symphony of slobbery squelches and sloppy sounds of pre-squirting out and landing on the floor, which had also become a wriggling mass of tentacles. “Breed You. Mount You. Fuck You.” The tendrils began rising, growing taller and longer and closing around the two fucking monsters, more specifically enclosing around Doggo. 

“Do you want to fuck me?” Asgore purred. 

“Yes.” Moaned Doggo, fully intoxicated to the dark ecstasy that was taking him over. “W-Want to fuck you.” 

“Do you want to mount me?” 

“W-Want to mount you!” 

Asgore leaned close, lips kissing Doggo’s ears. “Do you give into the hive? If you do, then you can breed me, my dear Doggo. Give into the hive, submit yourself to the hive, and you can have me to fuck, to mount, to breed. You want that, don't you?” 

“Yes! Yes!” Doggo’s thrust became brutal as he was treating Asgore’s asshole like a fucktoy and wasn’t stopping his movements, having found a perfect rhythm to really grind his dick and, more importantly, grind his knot into Asgore’s swollen ass-lips and trying to force his knot inside of him. “I give in! I submit! I give into the hive!” 

“Good!” The tendrils descended upon him, enveloping Doggo while his dick was still inside of Asgore. The tendrils wrapped around Asgore’s lower body, keeping him partially inside and rewarding Doggo with a treat for being so well behaved.

Inside the cocoon, Doggo had lost himself to his animalistic carnality as he was fucking Asgore with the intention of ensuring that his knot would get inside Asgore’s ass. The orange-sized sphere, huge and slippery, squelched against the royal entrance, demanding to get inside, trying to tie the two of them together, and from the snarls and growls that his guard was releasing, it wouldn’t be long until…

POP!

Doggo and Asgore both howled/squealed as the knot popped through, pushing Doggo deeper inside of him. Cords of sloppy watery doggy pre-flooding Asgore’s anal passage and Doggo’s hips jerked back and forth only to thrust in deep enough for his knot to fully lock in place and then swell before he came with a snarling howl. His abs flexed, his balls pulled upward, and he groaned once more, shoving his dick in as he came with a literal tidal wave of thick, hot seed gushing into his ass.

It was just pouring, and pouring, and pouring and pouring. There almost seemed to be no end to it, as Doggo’s balls pulsed against Asgore’s ass cheeks while he gave slow shallow thrust against the King’s rear, his seed was still filling him, filling in every single nook and cranny of Asgore’s tight passage dumping a load of hot doggy spunk deep into the phillant hole that was milking him for every single last drop of his essence that he could manage to give it and Doggo had a lot to give just as Asgore’s ass was taking it all. 

As he came, Doggo completely missed how the voice purred in his mind, and he could only make out one thing. “Good boy, you belong to us now.” 

Outside the cocoon, Asgore was moaning happily, watching his belly slowly swelling, cum gurgling as Doggo unloaded his load and filled his guts, softening the spike of his cock, stretching out his belly and gradually flooding his insides with his semen as his cock kept pumping, continually pissing out gallon after gallon of thick, canine cum into his sloshing guts. “Come Doggo.” Cooed Asgore, watching as the cocoon shuddered and trembled. “Come to me, my darling knight.” 

Outside the cocoon, something began to form from it, first a pair of legs with clawed feet, followed by a body, then arms and legs, and lastly the rest of it. It was Doggo, only he was different. Doggo’s body was covered in smooth, black, leathery skin; not only that, but he had grown! Doggo now sported a muscular figure that included bulging arms, thick legs, a set of six-pack abs, large, firm pectorals complete with dark nipples the size of quarters, a large, perky bubble butt, and even if his cock was sealed inside of Asgore, it had grown as well becoming a monstrous 32-inch long 10-inch thick cock with balls the size of coconuts. The suit along his body had changed the color of his fur, becoming a shade of blue that looked almost black. He had black claws on his hands and feet, and bright blue studs jutted out of his wrist and neck with small symbiotic chains connecting to them. At the center of his chest was a glowing symbol looking like the Delta rune seen as a symbol of the prophecy that released a set of small rainbow energy wings, but the center of it looked more like a snarling dog's head than the normal symbol. 

“My dear knight.” Purred Asgore, reaching out to take Doggo’s face between his hands. “You look absolutely ravishing.” He mewled as Doggo growled, looking him in his eyes. “But I can tell you want more.” 

“Of course, my king, after all.” He leaned in close, their faces mere inches apart. “I must do my job and make sure you can birth more eggs for the hive.” The two didn’t waste a single moment as they made out arms interlocking as Doggo resumed fucking him, his knot having softened enough, got him to start moving and start fucking him. As they did so, the ground beneath them, covered in semen, began bubbling and churning, the thick semen turned pitch black and began growing larger as it started spreading across the ground seeping into the cracks and spreading through the castle. 

At the same time, much of the room they were in began to become infested with more tentacles that started to crawl along the walls and the ceiling, crawling their way out of the room as if in search of their next target.