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Part 11 of Dad for One Short Fiction
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2021-05-29
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How NOT to Adopt a Pet

Summary:

Sea dragon All for One has noticed that his brother has gotten more depressed than usual in his cave (cough vault cough) so he decides to adopt a pet. Hey, look, some mermaid left a perfectly good child unattended! Mer Izuku is too cute not to take home, and it’s especially adorable how he keeps trying to murder All for One.

Notes:

The brilliant breadgoddoesart /migu-arts drew a terrifying picture Sea Dragon All for One menacing mer Izuku. Check it out at:https://aimportantdragoncollector.tumblr.com/post/665534434955673600

(See the end of the work for more notes and other works inspired by this one.)

Work Text:

Izuku swam alongside his mother. The underwater marketplace bustled around them. Mermen stood next to nets full of fish, shouting their prices. An elderly mermaid had her handcrafted jewelry chained to her stall to stop it from floating off. Sitting behind colorful tables, merchants hawked all sorts of wares, from beautiful kelp shirts to fin growth tonic.

“Does the beautiful lady desire perfume?” Smiling, a man with the bottom half of an octopus held up potion bottles in his many tentacles. He must be a cecaelia, a traveler from the northern waters.

Inko shook her head and kept swimming.

A blond mermaid wearing a shimmering scaled blouse called, “Buy one comb, get one free!”

Inko stopped to look at the glass case. “Those do look pretty.” Her eyes lingered on a pearl comb.

“You should treat yourself, Mom,” Izuku said. “We sold our last batch of kelp at a great price.”

“Your son is right,” the mermaid said with transparent self-interest. Her eyes fell on Izuku. She blurted out, “What happened to him?”

Izuku’s shoulders hunched. Both he and his mother had tails as green as their hair. But Izuku’s tail was shorter and shriveled. He didn’t even have fins on the end, so his mother had crafted two wooden triangles to strap to his tail. Without them, he could barely swim.

“That’s how he was born. About the combs, are they all the same price?” Inko asked, clearly trying to change the subject.

“Aw, the poor little thing.” The mermaid sighed. “What a good little boy you are, helping your mother go shopping.” Out of the corner of her mouth, she asked, “He can understand me, right?”

“Yes, I can understand you,” Izuku said wearily. He was twelve years old, nearly thirteen, yet she spoke to him as if he was a toddler. People often treated him differently after seeing his tail. He disliked the babying even more than the bullying.

Inko’s mouth flattened to a thin line. “Good day,” she said curtly, turning away.

Izuku swam after her. He knew it would do no good to tell her he didn’t mind if she brought herself a comb. She’d already decided. Instead, he murmured, “I’m fine.”

This won him a small smile from his mother. “I know you are. You’ve always been one of the strongest people I know. I’m proud of you.”

No matter how other people treated him, Izuku knew that his mother loved him. That was more important.

A massive rock hurled through the water, sending two stalls flying. As wood and other fragments hit the crowd, Izuku and Inko were knocked apart.

Izuku spun in circles, impacting with an abandoned stall. He screamed in pain as the table fell on top of his tail. Around him, the wailing of the crowd rose to a panic.

The massive stone wall surrounding the town had been breached. A sea dragon floated through the hole.

This serpent could have encased the entire marketplace with his tail. Unthinkable, for one to grow so large. He had scarlet scales with a white belly and ridges running down his back. Two curled horns grew from his head and a white mane flowed over them. Red eyes gleamed as he opened his mouth to reveal many teeth, each one taller than Izuku’s whole body.

Sea dragons ate mers. The bloodthirsty monsters were known for devouring anything they could sink their teeth into. At this point, Izuku realized that his artificial fins had broken when the stall had fallen on him. He couldn’t swim.

“Izuku!” Inko wept gushing tears as she swam over the crowd of fleeing mers, calling for him. His body remained hidden from view behind the broken table.

The comb-selling mermaid said, “I saw your son fleeing that way, toward the evacuation caves.” She sounded like she sincerely believed it. Izuku got the feeling that she wanted to believe it, so she’d be able to head in that direction herself without feeling guilty about abandoning a crippled child.

“Oh! Thank you!” Inko turned to swim away.

Izuku could have called out to stop her. But. His tail was stuck under the fallen wood. It would take precious time to free him, then his mother would have to carry him. He understood with hideous clarity that if burdened by him, she wouldn’t be able to make it away from the dragon in time.

He kept silent.

As the screaming crowd faded away into the distance, the only sound came from the approaching sea dragon. Enormous waves shot out from each movement of his tail. His body cast a shadow over the deserted marketplace.

Izuku had heard tales of a sea dragon with white scales and blood-red eyes. For his voracious appetite, the mers called him All for One. He never left survivors.

In a booming voice, the dragon complained to himself, “For such small things, mers do swim fast. I knew I shouldn’t have wasted so much time eating the guards.” His open mouth gave Izuku a good view of the helmet still stuck to one of his teeth. “There must be at least one morsel around here—” His nostrils twitched. “Ah-ha!”

In a swift dive, the dragon’s head appeared in front of Izuku. The stench of blood and meat came from his mouth. He had a long snout with catfish-like whiskers. Izuku prayed his end would be quick.

The dragon looked down at the trapped merboy and hesitated. “Your eyes…they’re the exact same shade of green as my brother’s.”

Those would be stupid words to die to. In a last gesture of defiance, Izuku picked up a broken piece of wood and hurled it at the dragon’s eye.

Laughing, the dragon easily crunched the wood between his teeth. “You’ve got his temper, too! I bet you two would get along fabulously. That gives me an idea.”

As the sea serpent’s jaws fastened around him, Izuku expected death. But instead, the dragon picked him up and carried him away.


The dragon stopped in front of a massive cave with a boulder in front. Using his tail, he rolled the boulder away.

Inside, a second sea serpent curled up in a ball, sleeping. He was maybe half the size of All for One, with green scales and a long white mane. He didn’t look well. His bones showed through his tail and his scales flaked. How strange for the infamous All for One to tolerate another in his cave. Sea dragons were notoriously territorial and cannibalistic. They would have long ago overrun the ocean if they didn’t keep eating each other.

The smaller dragon cracked one green eye open. “Back already, Hisashi?” His tone suggested the other would have been welcome to stay away longer.

“Little brother, you kept complaining about being bored, so I brought you a pet.” Hisashi opened his mouth to reveal Izuku inside, wet and terrified.

Horror filled the younger brother’s eyes. “That’s not a pet! That’s a person!”

“If you don’t want him, I can always swallow him right now,” Hisashi said.

The smaller dragon immediately switched tactics. “Ha-ha, he’s great, the best thing ever you ever got me, I love him already!”

Izuku did not appreciate being a pet, but it beat being dinner. Using his arms, he swam out of the mouth while it was still open. Just moving a short distance took so much effort his body shook with exhaustion.

Hisashi said, “This is my younger brother, Yoichi. Yoichi, this is—”

“Izuku,” he quickly said before he could be given a ridiculous pet name.

Hisashi looked disappointed. “I was going to name you Green Eyes.”

“That’s stupid and uncreative, big brother.” Yoichi reached out with his tail and yanked Izuku behind him protectively. “Nice to meet you, Izuku. I wish it were under better circumstances.”

Hisashi said, “Yoichi is far too small and fragile for the dangerous ocean, so I keep him safe in here.”

Izuku looked up, and up, and the dragon. Yoichi was several times the size of the house where he lived with his mother. This is tiny? Well, perhaps by Hisashi’s standards. The strangest part of this living situation was that the larger dragon hadn’t yet eaten the smaller one. Perhaps Yoichi had survived by being too weak to be considered a rival. That, or Hisashi was saving a snack for later.

Out of the side of his mouth, Yoichi muttered several swear words expressing his feelings about his brother’s protection. Izuku started to hope he might have an ally here.

“Try not to break the pet, it would be a pain to find another one with such nice eyes,” Hisashi said. “I’m sure you’ll be so grateful for my gift that you’ll even eat a bit of food tonight. I’ll make some dinner for both of you.” Something about the way the dragon said that gave Izuku a bad feeling that his role was intended to be as much hostage as pet.

Yoichi nodded frantically. “If you’re keeping Izuku here, which I definitely don’t agree with, you must feed him!”

“As long as you eat, too,” Hisashi said. Yes, that had been a threat. Just great.

As the larger sea dragon bustled around the other end of the cave, using magic to lift dinner ingredients, Yoichi whispered, “It’s okay. I won’t let him hurt you.”

“Can you stop him?” Izuku asked.

Yoichi winced.

“Sorry, I wasn’t asking that to be mean. I just want an idea of my chances.”

Yoichi exhaled so hard a lock of hair blew off his forehead. “My track record stopping my brother isn’t great, but I’ll protect you with all my power. He wants me to stop trying to escape him, so that gives me at least a little leverage.”

Izuku had already been wondering about the boulder over the cave entrance. So they were both stuck in this place. “Why did he trap you in here?”

“It all started when I tried to persuade him to stop eating merfolk.”

“Excellent idea. As a mer, I thoroughly endorse that plan.”

“He wouldn’t listen to me at all, until I threatened to leave and never come back. Then he locked me in here.” Yoichi’s whiskers drooped. “I tried to fight him, but he’s a lot bigger than me. And I don’t have any magic.”

So Hisashi hadn’t eaten his brother because he was possessive. From a scientific standpoint, how interesting and unusual. “Maybe you might grow more,” Izuku said encouragingly.

“Unfortunately, I’m the runt of the nest. This is as big as I’m going to get. I’m a fully matured adult, although good luck convincing my brother of that.” Yoichi sighed.

“I completely understand how you feel.” Izuku gestured at his tail. “People patronize me all the time because of this. That, or they bully me.”

“Exactly! My own mother tried to eat me as a child.”

“My mom is awesome, I got lucky there. She must be so worried about me…”

“I’ll help you escape, I promise.” Yoichi smiled gently. “It would be easier if I could drug my brother, but last time it had no effect.”

“Ah, poison, I was just thinking that!” Izuku nodded. “Do you think maybe you didn’t use enough?” He spoke diplomatically. Although Izuku would be happy to murder the giant sea serpent, it wasn’t clear if his brother would feel the same way.

“At first, I was being super-careful not to kill Hisashi. I mean, he did stop our mother from eating me. He’s still my brother no matter what. But then he had the nerve to steal my haircare products. He said he wanted a nice, fluffy mane like mine. I spent months brewing those potions. Now my hair is sad and flat because he took them all for himself.” Yoichi’s eyes narrowed. “So I tripled the poison dosage.”

“Sounds like a normal and proportionate reaction to me. No jury under the sea would convict you.”

“Hisashi said the food was delicious. He asked for more of whatever spice I used next time. Then he went around for a few weeks breathing poisonous gas.”

“It made him stronger?” Izuku groaned. “I guess I’d better sneak out while he’s gone.”

“That’s probably for the best. Fighting him doesn’t—” Yoichi cut off as his older brother returned.

Sea serpents had no hands. Hisashi used his magic to float a bowl of kelp forward. “I don’t have any smaller bowls—can you break off some for your pet?”

“You eat kelp?” Izuku blurted out before he could stop himself.

Yoichi raised his snout and sniffed. “I’m a vegetarian.”

“I thought dragons were carnivorous.”

Hisashi said wearily, “We are, he’s a moron, that’s why he’s gotten so sick.”

Izuku hesitated. Whereas honestly compelled him to point out that carnivores couldn’t survive on a vegetable diet, he stood to gain nothing by persuading one of the two predators he was stuck in a cave with to eat meat. “I like kelp.” Even if he’d gotten sick of it, coming from a family of kelp farmers.

The kelp was exquisitely spiced. Better cooking than Izuku had expected from a notoriously murderous sea dragon.


By the time he’d finished eating, Izuku had started to be able to believe he wasn’t going to be immediately murdered. He looked around at his surroundings.

The cave was full of loot likely taken from mer cities. Several mosaics hung from the walls, showing a coral reef, a human shipwreck, and the bushy-bearded sea god with his trident. Gemstones peeked out of a chest in the corner. Stone tablets filled the high bookshelves. The back corner had a close-topped caldron and bottles for brewing potions. A golden crown decorated the top of a dragon-sized cushion with a high back. It gave Izuku an odd feeling to recognize the gems on the crown formed the crest of a fallen mer kingdom, destroyed by All for One.

Hisashi bustled around the cave, lifting items with his magic. He created a mer-sized bed by hollowing out a cushion. Then he clawed out a small cup from a piece of wood.

Just as Izuku started to relax, Hisashi said, “I read a treatise on caring for pets.”

Out of the corner of his mouth, Yoichi muttered, “Oh, dear, my brother with a little knowledge is a dangerous thing.”

“The handwriting was rather small, but there was mention of grooming.” Hisashi produced a giant scale polisher made of soft cloth attached to a handle. “He’s a bit scruffy looking, but with a bit of polish, that tail will shine!”

Izuku backed away. Objecting seemed suicidal, but being hit by a brush that large might kill him and he didn’t trust the sea dragon’s gentleness.

Yoichi leapt forward, wrapping his tail around Izuku. “If he’s supposed to be my pet, then that would be my responsibility.”

“But I thought it looked fun.” Hisashi pouted.

Yoichi snatched the brush with his jaws and ripped off a bit of cloth. Tossing it down at Izuku, he hissed, “You can use that if you like, but your scales look fine to me.”

“Thanks,” Izuku said, considering himself to have had a close save.


Unfortunately, the next morning, Yoichi was sick.

The younger sea dragon lay curled in a ball, moaning.

Izuku rose from his bed, where he’d barely managed to sleep a wink. He dared touch the green scales. The dragon didn’t feel feverish. He glanced at Hisashi. “Do you have medicine?”

Hisashi said, “He has a stomach ache because he ate plants. Because he’s a carnivore.” He raised his voice on the last word.

Yoichi moaned even louder.

“There’s nothing for him to do but rest until he flushes the kelp out of his system.” Hisashi’s exasperation turned to delight as his eyes fell on Izuku. “I’ll be happy to look after you.”

Izuku flinched. The dragon pounced.

Within seconds, Hisashi had Izuku wrapped up in his tail coils. They felt comfortably warm, yet the merboy still trembled.

Looming over him, Hisashi’s mouth held the brush. “Grooming time!” he said with inordinate glee.

To Izuku’s surprise, the touch of cloth against his scales was gentle. Then the dragon licked him.

Izuku screamed, believing he was about to be swallowed whole.

“Sea dragon saliva is good for the scales,” Hisashi said. “Calm down.”

Afraid to annoy his captor, Izuku lay still. Hisashi remained oddly gentle, even when he got out a tiny comb and ran it through the green hair.

Afterward, Izuku hoped to be released, but instead Hisashi curled tighter around him. The dragon made a low noise like a purr.

“Are we done here?” Izuku asked desperately. He hated being babied more than anything. It gave him flashbacks to how that patronizing shopkeeper had treated him.

“It’s so rare for me to meet anyone I can tolerate this long.” Hisashi purred again. “You’re so cute, like a doll.”

Opening one eye, Yoichi rasped out, “The next person who wakes me up dies.” For once he sounded scarier than his big brother.


Shortly after Hisashi left to go hunting, Yoichi emerged from his deep slumber.

“How are you—?” Izuku stared to ask him.

Yoichi shot past him, then vomited into a bag. Wiping his mouth, he said, “Much better now, actually. At least I no longer feel on the verge of throwing up now I’ve gotten that out of my system.”

Izuku ventured to pat the green scales in comfort.

Yoichi took a gulp of the surrounding water, then said, “Time to work on your escape.”

Entirely in favor of this, Izuku asked, “Do you have any wooden boards? I need to build an artificial tail fin.”

Yoichi ripped a wooden decorative plate off the wall. Under Izuku’s directions, he sliced it with his fangs into the correct shape. Then they fastened on the wooden fin with cloth strips.

Izuku waved his new tail. “It’s not as good as my old one, but I can swim.” Even knowing he was still trapped, the ability to move at a pace above a crawl made him feel so much better. “But how am I supposed to get out of here?” He eyed the giant boulder blocking the cave entrance.

Yoichi said, “No chance I could lift it away to escape myself, but I might be able to move it just enough to create a crack for you.”

Izuku’s spirits rose. “Worth a try.”

But no matter how Yoichi grunted and strained, he couldn’t shift the boulder. The dragon collapsed to his belly on the cave floor, mumbling, “So…hungry…”

Izuku hesitated. Finally, he said, “I don’t think eating kelp is very good for you.”

“I know that,” Yoichi groaned. “I don’t mind eating fish and other unintelligent sea creatures. But I’m afraid to eat any meat my brother brings back because he might slip in merfolk.”

Izuku paled. “He’d do that?”

“He’d do it just to lord it over me later.”

“I’m smaller than you. What if I spy on him preparing the next meal? I could tell you if the food is safe to eat.”

Both Yoichi’s eyes shot open. “Sounds like a plan.”

When the boulder finally ground away from the entrance, Izuku watched carefully. To his relief, Hisashi carried a giant shark between his teeth, not merfolk.

Izuku crept behind a table leg and watched. His eyes kept drifting shut due to his lack of sleep the night before. But he was able to confirm that Hisashi sliced up strips of the shark into bowls, and nothing more.

As soon as Hisashi set the bowls down, Yoichi looked at Izuku.

“They’re safe.” Izuku nodded.

“Oh, what a relief.” Yoichi fell upon the shark meat with slavering jaws. The ripping noises were truly terrifying to mer ears.

Hisashi stared at the two of them. “You got him to eat?” He shook his head in amazement. “Little Izuku, you’re the best idea I had in a long time. You deserve a reward.”

Izuku chuckled nervously, worried about what that might mean. “I did nothing. Really.”

“Quite ingenious of you, to create your own fin like that. How about some pearls to drape over it?”

Was that all? No forced cuddling again? “Pearls, sounds lovely.”

Izuku could care less, but he pretended gratitude as he tied the pearls over his tail and considered himself to have gotten off lightly.

Then Hisashi reached for the brush, and Izuku’s spirits plummeted.

“There’s no need,” he said, backing away. Even the vainest of mers didn’t polish their scales every day!

“Leave him alone,” Yoichi growled, wrapping his tail around Izuku again.

This time, instead of leaving, Hisashi coiled his even larger body around both of them.

“Hey!” Yoichi yelped. He tried to escape, but his brother’s tail settled on top of his, pinning him down.

“Isn’t this nice?” Hisashi hummed as he brushed Izuku’s tail.

He got two groans in return.

Izuku was eager to turn into bed, since the next morning would herald an escape attempt. Unfortunately, Hisashi showed no signs of moving. Eventually, Izuku’s exhaustion let him fall asleep in the coils of a predator.


Izuku woke up back in his new bed. He fastened on his fin, slouched over to Yoichi, and grumbled, “Your brother is insane.”

“You’re preaching to the choir.” Yoichi unwound his tail and stretched to his full length. “Let’s get you out of here.”

The sea dragon spent hours of heaving and groaning against the boulder. Izuku watched with baited breath. Eventually, Yoichi collapsed to the cave floor, panting. “I’m…sorry.”

“That’s okay,” Izuku said. “You’re probably still recovering from starvation. It was optimistic to hope that you’d be much stronger after only one day of eating.”

“I’ll try again tomorrow. I promise.” Yoichi curled up and fell asleep.

Izuku felt genuinely grateful to the sea dragon for trying so hard to help him. He wasn’t ignorant to the fact that Yoichi might get in trouble for letting him out. But he didn’t have any other options.

Could he do something nice for Yoichi? What did dragons like besides eating? They were notorious for loving gold and other treasures.

Izuku looked around the cave, which was already decorated with gemstones and piles of gold in the corners. He spotted a treasure chest lying sideways with several dents in the metal. Someone had been trying—and failing—to open the box.

From his work around the farm, Izuku had a bit of experience with mechanics. He found a wire lying among the treasure pile and set to work. In a matter of minutes, he’d opened the chest. A giant emerald gleamed inside.

The boulder rumbled and moved. Hisashi had returned.

Izuku darted into Yoichi’s bed of giant cushions and hid behind the dragon’s tail. He watched as Hisashi dragged in a manta ray so massive he had to twist it to fit into the cave. Thankfully, still not merfolk.

After stashing his prey in his freezer box, Hisashi’s eyes fell on the treasure chest. “Oh! I’ve been trying for weeks to get that open.” He swum over. “The gem is my favorite color, too. Aw, Izuku, did you do this for me? I guess having someone with hands around can be helpful.”

Izuku said, “Actually, that was for—”

Yoichi opened his eyes. “For you!” He hissed, “It’s important that my brother like you, in case he gets hungry late at night.”

Izuku took the point.

“You deserve another reward,” Hisashi said. “What would you like?”

“Please, let me go outside.” Izuku saw a chance. “It’s not healthy for me to remain cooped up inside all day. Wasn’t that mentioned during your research into care for pets?”

“The tablet did say something about exercise.” Hisashi vanished to the back of the cave and returned with a long chain. “Here! Now I can take you on walks. It will be so much fun.”

Izuku flinched away from the horrible metal object while a brotherly argument began.

Yoichi shouted, “You can’t walk a person around on a chain! That’s horrible! You’re treating him like an animal.”

Hisashi sniffed. “Nonsense, I’d do the same thing to you if I could find a chain big enough.”

“I know you would, that’s kinda the whole problem.” Yoichi’s eyes narrowed. “The chain links are wider than his entire body, how do you propose to fasten it?”

This practical concern proved more of an obstacle than the ethical one. To Izuku’s relief, Hisashi conceded there was no way to fasten the chain.

Instead, the dragon rummaged through his treasure pile muttering about exercise. He emerged with a broken marble pillar and a collar covered in seashells. “Do you want to play a game of fetch? Or a new piece of jewelry?”

“Err…” Izuku stared at both items in unabashed horror. The pillar would probably kill him if it got thrown at him, and he considered death a real choice compared to the collar. He whispered to Yoichi, “Do I really need to go this far?”

Yoichi straightened to his full height. “Big brother, I’d rather play the murder game.”

“Oh, that sounds like fun.” Hisashi laughed. Izuku hoped the game was less ominous than it sounded.

Tail lashing, Yoichi leapt for his brother’s throat. Hisashi slapped him to the ground.

As they fought, it quickly became evident to Izuku that 1. Yoichi wasn’t playing at anything, he was flat-out trying to rip his brother’s throat out and 2. Hisashi thought this was great fun.

Finally, Hisashi pushed Yoichi down and sat on him. Yoichi made little growling noises.

Hisashi laughed. “My victory again! Do you want a turn, Izuku? Either fight me or I’ll teach you how to do flips.”

Izuku most certainly did not want a turn, but he didn’t want to be forced to do tricks either. “How about fetch?” He picked up the emerald from the chest and threw it toward the kitchen.

“Ah!” Hisashi lunged to catch the emerald. Yoichi took advantage to jump on his brother’s back.

As he tried to throw his little brother off, Hisashi said, “That was a nice trick! Much better than a backflip.”

“So glad you think so,” Izuku muttered. “Am I the only one who’s hungry?”

Hisashi seemed just as pleased that Yoichi ate dinner again that night, after Izuku signaled it was safe. “You’re a little miracle-worker, Izuku. I’m so glad I picked you as my pet.”

Yoichi said, “You mean my pet.” It was obvious from his worried tone he was only saying this to protect Izuku.

Hisashi smiled, barring his teeth. “Yeah, of course, our pet.”

Izuku had a feeling he’d better get out of this cave as soon as possible.


As soon as Hisashi left the next morning, Izuku and Yoichi headed for the boulder again.

“Can I do anything to help?” Izuku asked.

Yoichi eyed the massive rock. “Just make sure you stand back so it doesn’t hit you. I’m feeling strong after tasting my brother’s blood yesterday. I think I can do this.”

The first hour consisted of huffing and groaning again. With one last head-butt, Yoichi managed to roll the boulder just a crack away. The sea dragon collapsed, wheezing.

Izuku swam up to the gap. “It will be tight, but I can slip through.”

“Good luck, Izuku.” Yoichi raised his head off the floor. “It was lovely to meet you, and I mean it in the kindest way possible when I say I hope to never see you again.”

Izuku grinned. “Same here. Thank you. I’ll never forget your help.”

The sight of the open ocean made Izuku’s heart race with joy. Sea anemones spread out in all directions, dotting the sandy floor. A jellyfish floated past him. He didn’t know exactly where he was, but if he headed toward the underwater volcano in the distance, he’d find himself back in mer territory. He’d see his mother again! Maybe he could even find someone powerful enough to move that boulder and help Yoichi escape. With a light heart, Izuku swam.

He passed the carcass of a whale. Little fish swam around the bones. Izuku stopped and broke off part of a rib bone. He felt more comfortable with a weapon.

When he first heard the rumblings of a large creature, he froze. A school of fish fled past him. He knew what that meant. A predator.

It had to be a coincidence. Hisashi was still out hunting. He couldn’t know that his “pet” had gotten loose.

Just in case, Izuku needed to hide. He found a brilliant mixture of red, blue, and yellow brain coral growing next to a pile of rocks. There was a gap between a boulder and the reef. He dove into the hole and curled up.

The boom of water being pushed away announced the sea dragon’s procession forward. Izuku clamped a hand over his mouth to stop his teeth from chattering.

With one massive sweep of his tail, the sea serpent ripped the coral reef from the sand. Big red eyes peered down. Hisashi smirked. “Playing hide and seek, pet?”

Izuku was too terrified to reply.

“I have a very keen sense of smell. Once I remember a scent, I can track it for miles around.” Leaning close, Hisashi whispered, “And you have a very nice smell, pet.”

“Why, thank you,” Izuku gasped out, near-hysterical.

“Imagine my surprise when I smelled you so far from my cave.” Hisashi scooped the mer up in his mouth. “Let’s head home, little one.”

Izuku’s temper snapped. He’d gotten so close to seeing his mother again. Now this oversized snake was patronizing him. He yanked out the whale bone from behind his back and rammed it into the dragon’s mouth.

Hisashi howled. His jaws opened. Izuku swam faster than he ever had before.

“Ooo, someone wants to play the murder game!”

Izuku discovered that he could, in fact, swim even faster. The stench of blood filled the water. He fled toward a sandy hill ahead, hoping to hide.

Just as he rounded the hill, it exploded. Hisashi had demolished it with one swing of his tail. The sea dragon grinned, barring fangs dripping with blood.

With shaking hands, Izuku raised his bone.

Hisashi grinned even broader. “You have the spirit of a dragon!” He lunged.

Izuku got one scrape on the dragon’s scales, then Hisashi seized the bone with his fangs and wrenched it away. At close range, his rotting breath smelled terrifying.

Hisashi wrapped Izuku up with his tail and swam back, humming. They shot through the water so fast that Izuku felt his lips peel back from the pressure. He couldn’t even summon up the breath to scream.

Yoichi gasped upon seeing them. As soon as Izuku was released inside the cave, he swam behind Yoichi, terrified he’d been brought back only to be turned into dinner.

First, Hisashi hauled over an even larger boulder to block the cave off, all the while muttering about custom-built cages. Izuku had many concerns.

Then Hisashi addressed his little brother. “How could you be so irresponsible? You can’t just release your pet into the wild! He doesn’t know how to survive!”

Izuku blinked. He supposed one advantage to his lowly status as a pet was that he could evade responsibility for his own actions.

Yoichi reared up to his full height. “He’s not a pet, you crazy bastard! He’s a person, and you kidnapped him! He has a mother who loves him and must be missing him terribly.”

Hisashi cocked his head. “So, you’ll stop whining if I bring back his mother?”

Both Yoichi and Izuku screeched, “No!”

Hisashi winced. “No need to break my eardrums. If you’re going to be so childish, little brother, then I’ll have to remove your pet from your care and take him into my own.”

“Nice excuse. You just want more cuddles and grooming sessions,” Yoichi grumbled.

“Just look at him!” Hisashi inclined his head at Izuku. “With his poor tail, he’d never last as a stray.”

Izuku couldn’t control his mouth. “I’ve looked after myself just fine for twelve—nearly thirteen—years.”

“You’re only twelve years old?” Hisashi looked ready to faint. “An infant! Barely out of the egg.”

Yoichi said, “He’s a mer, not a dragon. That’s probably practically adult for their kind.”

Neither assessment was correct, but Izuku preferred Yoichi’s. “That’s right, I’m perfectly capable of defending myself.”

Hisashi grinned. “You have the violent nature of a dragon. I like that. Little brother, would you believe he landed two hits on me?” He opened his mouth to show off the cut. Far from sounding angry, he seemed proud. “I wish you would try harder to kill me like that. Your bites are always half-hearted, and you’re clearly not using enough poison. If you keep on holding back, I’ll think you don’t love me as much as Izuku does.”

Izuku blinked. Murder was a sign of affection for sea dragons? It made a worrying amount of sense.

“I am trying, I promise,” Yoichi said. “That’s a good injury. Nice job, Izuku.”

“I completely underestimated him. He’s such a cute little one!” Hisashi patted Izuku with his tail. “Hmm. I’ve felt this happiness before. It’s the sensation of wanting to eat something, but if I did, he’d be gone forever. I must really like you, Izuku. Welcome to the family!” He bustled off to prepare the next meal.

Izuku stared. “What just happened?”

Yoichi sighed wearily. “The Devil officially welcomed you to hell.”


Hisashi prowled through the ocean, looking for a nice treat to bring back for dinner now his brother was finally eating meat.

In the distance, he scented a mermaid. A rare delicacy! Hisashi changed his course.

Was it too much to hope that his little brother would try merfolk flesh? Probably, yes. Maybe he wouldn’t notice if Hisashi slipped it in among some shark meat. Then once Yoichi ate it, he’d have to admit that he liked it.

Hisashi swam more slowly as he approached his target, this time taking care not to reveal his presence.

From behind a rock, he spotted a green-haired mermaid. Her hair was bedraggled and her face stained with tears. She had the exact same scale color as his little one. She cried, “Izuku! Izuku, where are you?”

Hisashi’s eyes widened with delight. He leapt out from behind the rock. “You must be the mother!”

The mermaid screamed and attempted to flee, but Hisashi had already caught her between his jaws. He hummed to himself as he headed back to the cave, carrying the sobbing mermaid with him.

Yoichi had insisted that Izuku wouldn’t want his mother to be brought back. But Yoichi had no idea what was best for himself, much less other people. Hence why he kept trying to leave the nice, safe cave his older brother had lovingly provided for him. Even though he was far too tiny and weak a dragon to survive alone.

Hisashi had the perfect plan: once he gave his little brother this new pet as a replacement, Izuku would belong solely to him. Furthermore, Izuku would be so happy to be reunited with his mother that he’d stop trying to run away. He just couldn’t wait to see the merboy’s delighted face! Tail wagging, Hisashi swam, ignoring the sound of screaming coming from his mouth.


OMAKE TIME!

Omake: Sea Dragon Logic

Hisashi: Sea dragons show affection by murder…but my little brother is so small, he can barely take a hit. I need to restrain myself.

Yoichi: Whoa, by sea dragon standards you’re quite cultured.

Hisashi: Vaulting is the best solution here.

Yoichi: I take it all back.

#

Omake: Sibling Rivalry

Hisashi: I’m not sure why Izuku likes you more when I’m the one mainly looking after him.

Yoichi: Because I’m the pretty one?

Hisashi: If I get some scale polish…and borrow your shampoo again…

Yoichi: Keep your thieving tail off my hair products. Last time, you used the whole bottle at once, you philistine. It made your mane as greasy as your soul. I was joking. Izuku hates you because you kidnapped him.

Hisashi: Ridiculous, of course he likes me.

Yoichi: Apparently I’m the smart one, too.

Hisashi: You most certainly are not!

#

Omake: Famous Last Words

Yoichi: I have a plan. Let’s make my brother like you. Maybe then he’ll develop empathy for merfolk in general.

Izuku: Do you seriously think that will work?

Yoichi: It can’t make anything worse.

Later:

Yoichi: It seems you’re getting along with Izuku now?

Hisashi: Absolutely! Just look at this stab mark. He clearly loves me.

Yuuto: So you’re going to stop eating merfolk?

Hisashi: What? No, of course not, my foolish little brother. I simply decided to adopt Izuku! Isn’t that great? Now you two can stay here together forever.

Yoichi: I was wrong, it can always get worse. New plan, Izuku: let’s make my brother hate you.

Izuku: That sounds like more fun anyway.

Later:

Izuku: (Creeping in the dead of night with a dagger) This time for sure…

Hisashi: Aw! My heart can’t take the cuteness!

#

Omake: Epilogue

Hisashi: Little brother, now that I got you a new replacement pet, this gave me an idea.

Yoichi: Once again, I must plead for you to let those poor people go. Your idea is no doubt something terrible.

Hisashi: It’s a great idea. I’ve always wanted a child of my very own.

Yoichi: The last time a sea dragon tried to court you, you ate her.

Hisashi: She got on my nerves. Unfortunately, sea dragon pregnancies last ten years, and it’s very rare for me to be able to tolerate anyone that long.

Yoichi: The ocean will be relieved to hear you’re not reproducing.

Hisashi: But for some odd reason, Izuku doesn’t bother me. And he’s such a ferocious little thing. Clearly a dragon at heart. So I purchased these sea dragon transformation pills off a witch. How do you feel about a new nephew?

Yoichi: I’m going to render you bald with my teeth.

Hisashi: But you like Izuku, too.

Yoichi: I like him far too much to inflict him with you as a father. Have at thee, villain!

Hisashi: Ow! Little brother, not the hair!

#Let’s be real, Yoichi won’t win that one #But at least Hisashi will be entering fatherhood with a bald patch

Notes:

This story is my first of two submissions for Mer May. It was inspired by A_Guest’s prompt:

Sea dragon All for One has noticed that his brother has been more depressed than usual in his cave cough cough vault cough cough and decides to bring him a pet, a young mermaid named Izuku.

The first part of the story was also inspired by another prompt from B_O_M_B:

Mer Izuku was born with a stunted tail. Unlike the other mers, he really struggles to swim and keep up. He knows he’s loved, and is determined to overcome this handicap. But one day predators breach their home, and he can’t swim away fast enough.

I also want to give credit to Konilt and Ashura_Akuma for helping me brainstorm ideas for this fic.

I foreshadowed this story in The Firsts Club with the brief reference to Sea Dragon First. Not to spoil anything, but second my Mer May story will contain Eldritch Dad for One.

Series this work belongs to:

Works inspired by this one: