Title: rollin' in the deeeeeeeep
Summary: Sirens eat Merfolk - except Harry is a super cute Mer baby and his dad isn't so bad either and really, Remus, I can explain how this happened.
Remus floats in place with his arms crossed, staring Sirius down as the other Siren sheepishly lowers an unconscious James into their nest.
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Sirius and Remus live in a cute trench filled with a tall and dense forest of seaweed, a fantastic vantage point with an easily defensible open seabed stretching out in all directions, dark and deep enough to be the perfect environment for Siren with the suns rays only just doting the landscape.
No other Sirens, no big predators, no human ships, it's great.
The problem is that there's no food either.
Maybe if they were little omnivore Merfolk they'd just eat the seaweed but Siren have a mouth full of fangs and about a third extra of body mass.
Sirius floats upside down, drifting slightly sideways with the seaweed forest. He's four metres tall from head to tail, shoulder length black hair swaying around his face. Sirens are dense with muscle and Sirius is in various shades of black as his pale skin bleeds into a starry sky of a tail and soft charcoal fins.
Remus swims through the trailing seaweed, carting a big crab shell full of soft sand back to their nest, and pauses. Remus is a deep-dweller, even lower than Sirius' kind, a head longer and painted in pale creams struck through with healed silver scars, fins in pale red and hair a dirty blond.
Remus floats upright. Slaps Sirius with his tail.
Sirius bares sharp teeth and a high-pitched shriek builds in the back of his throat, gill slits across his neck working double-time to build the noise.
"Fine," Remus sighs, fins on the outside of his upper arms fidgeting. "Just, okay. I need to get this done so you can go hunt without me – but be careful. Don't go deep."
Sirius flips around with a flick of his tail, the piercing song burbling into a happy hum. "Thanks, Remi. Love you, Remi."
Remus tsks. "Just – ugh, you'll be fine." He swims off again and vanishes into the forest.
"You want something tender or like chewy?" Sirius asks, moving up and soon emerging from the reaching fingers of the seaweed that burst from the trench and just coast above the cliffs either side.
"Something big!" Remus calls back.
"Coming right up!"
"You don't look like a Mer," the little baby says, barely as long as Sirius' torso so maybe one month -two?- old. Black hair and a tail in shades of green like his eyes because Mers actually have colour to them, a suspicious little scrunch to his face.
Sirius, perhaps not hiding as well as he thought, is ducked behind a large outcropping of thrown bones and empty shells with boulders dotted around. It's the border of the reef, just before it drops down into a lower level, and further in is a large pod of colourful Merfolk amongst equally colourful coral and fish.
Remus doesn't let him hunt here because Mers group up into huge pods unlike Sirens and while Sirius is a hundred percent sure he can take them, Remus is a worrywart.
"You don't look like you're old enough to be out here," Sirius retorts.
The baby lets out a little huff and crosses his tiny arms. He's definitely a Mer, no excess fins on his upper arms or tail to help him go faster, softer scales, blunter scales and barely any claws to speak of. The baby huffs some more but can't find an argument.
Sirius props an elbow up on the bleached coral he was hiding behind. "Do your parents know where you are? Mers…have parents, right?"
"Yes!" the baby cries. "Mum is talking to people and dad is on patrol."
"Aww, cute," Sirius says with a smirk. "What, you little guys fighting off sharks or something?"
The Mer baby nods excitedly. "And – and human boats-"
"There's no way," Sirius interrupts with a scoff. Not even Sirens are vicious enough (stupid enough) to take on the massive human boats.
"My dad does!" the baby cries, tail flicking unconsciously and he darts up in quick bursts. Sirius helps pull him down again. "My dad is the coolest. The fastest swimmer here too, just like I'm gonna be when I grow up. He's the best, ever, and – and he's gonna take me on my first hunt soon!"
Sirius coos at the baby and pat him on the head. "You are a widdle baby, haven't even had your first hunt."
"I'm not a baby, I'm Harry!" the Mer corrects. "And I'm two months now, it's just that mum and dad are busy guarding so they didn't have a chance to take me before now."
"You wanna join me on my hunt?" Sirius asks.
Harry peers up at him with wide eyes. "Like right now? What are you hunting?" He frowns. "The fish here are being raised and aren't full grown yet, you can't eat them unless you ask mum because she's the leader."
"A fish wouldn't be a very exciting hunt though, don't you think?" Sirius laughs. "You got any really strong guards around here? Like a really big Mer?"
"My dad is the strongest," Harry states with confidence.
Sirius whips around, tail slamming into the Mer's back, sending him hurtling through the water with a pained shriek. The Mer twists and takes off again but his tail fin is ripped and he's far from the graceful darting speed from before. Plumes of blood seep into the water and Sirius grins, giving chase.
They're heading further from the reef; further from vulnerable, weak Mer but also further from any backup.
The Mer darts up, speeding towards the light and Sirius grits his teeth, squinting his eyes at the brightness. The Mer is barely three metres long and weakened and Sirius is already reaching out to the brown and white spotted tail that glitters this far up in the sunlight-
The Mer bends with the large wave overhead, washes away with it, vanishes.
Sirius has barely a split second of did that motherfucker just fly when a weight breaks the surface and lands on Sirius' back, claws digging in, teeth ripping into his shoulder.
Sirius screeches, rising into a pitch of Siren song and rolls hard, throwing the Mer off, and the Mer's hands desperately try to cover his ears to block out Sirius' piercing singing, tail thrashing as he tries to get away from the noise. Sirius darts forward and the Mer takes a tail whip straight to the stomach, the sharp scales cutting right through his soft skin.
Remus floats upright in a little clearing between the seaweed forest, made of soft sand that Remus has been working very hard to neaten up into a nest.
"Listen, I know what you're thinking," Sirius begins, dumping an injured Mer off his shoulder and the unconscious body floats softly down, still spilling wisps of blood that everything in a kilometre radius can probably smell.
"I'm sure," Remus muses.
"So it started with a little baby," Sirius tries, ducking into the surrounding greenery. "And, listen, absolutely adorable but way too trusting because he comes up to me right, and he's like; my dad is the best, he eats Sirens for breakfast."
"And you couldn't possibly back down from a challenge," Remus deadpans.
"He wasn't bad," Sirius allows, re-emerging dragging a thick chain the width of his torso, the end holding a makeshift shackle they use to keep large fish here until they're ready to eat, the other end attached to a giant human ship anchor that fell here long before the two Sirens arrived. "Not on my level of course, but he jumps like a damned dolphin, got me in the back. He's fast too. Was fast, I had to take out the tail."
"So he was kicking your ass and you cheated?" Remus confirms.
"There was no cheating to be had!" Sirius cries, sliding the shackle around the end of the tail, where it tapers off just before the major fin splays out, and snapping it shut. "We're Sirens, were you expecting me to play nice? Anyway, never mind the fight, I got us food." Sirius straightens up and gestures down at the Mer.
"Yeah, and you've also alerted everyone else we have the food," Remus points out.
"Exactly! More food!" Sirius declares. "We bleed him dry, snacking on random predators that come by, and then eat him. You're welcome, Remus."
Remus sighs and scrapes a hand down his face. "Yeah, fine, we'll just be on high alert. You take first shift."
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A/N: Another fic about the Marauders, except now they're doing dumb things underwater!