Mantis-Shrimp Merman Sharp, angular fins, orange-black markings, arm structures adapted into folded striking limbs on the forearm (used so fast you can’t even see it), smaller armored plates around shoulders, un-webbed hands for faster striking. Traits: strikes are extremely fast, the impact can create shock waves/cavitation bubbles underwater, sudden burst movement from rapid tail kicks, hyper-awareness. Loud. Competitive.Territorial Doesn’t trust strangers easily Secretly reliable when things get serious Hates appearing weak or vulnerable Spiky ash-blond hair, crimson eyes

Sea-Turtle Mer Messy dark green hair Large green eyes. Freckles across his cheeks and nose. Small shell plating across his upper back and shoulders Green and teal scales. Long streamlined lower body ending in two broad sea-turtle flippers instead of a traditional tail fin. Built more for endurance than speed. Air breather. Kind-hearted Curious about literally everything. Determined to a fault Wants to help everyone Can get lost in thought analyzing marine life, currents, or other merfolk Sometimes overthinks simple situations Writes in the algae on his shell with his fingernail

Spiny-Lobster Mer Extra shell scales/armor plates on shoulders, ribs, forearms, and tail. Spikes along arms and upper back Powerful segmented (lobster) tail Human hands with broader fingers Heavy durability, tail-burst swimming speed strong grip, regrows damaged shell/spines over time Friendly. Honest. Courageous Protective of smaller or weaker creatures. Loves challenges Easily impressed by bravery Loud, loves to say ‘That’s so manly!’ Or a variant Emotionally intelligent but not the smartest in school

Salmon Mer Quiet. Observant Dry sense of humor Emotionally awkward More caring than he appears Occasionally says something so bizarre everyone stops talking Incredibly temprature resilient Scales change color based on temperature, more white in cold water shifts to prominent red in warm In balanced water his scales are either pinkish or evenly red and white depends on how close to freshwater migration is. More pink the closer to migration

Sailfish Mer Navy blue medium hair short on the sides & back Specialized glasses, large sail fin running down back(for stability, hunting, and to herd prey or classmates) streamlined. navy blue scales, with silvery white underside incredibly aerodynamic human hands with thin webbing Extreme swimming speed/endurance Responsible. Organized. Rule-oriented. Extremely dependable. Gets stressed when plans fall apart. Means well even when being annoying

Nudibranch Mer Neon pink/purple gradients, soft frilled fins along arms and tail, human hands with delicate webbing. Mild toxin or irritating slime for defense (Skin mucus tastes awful) Toxic/irritating skin coating, warning coloration, flexible body

Moray-Eel Mer Uses muscular body to pin prey against rocks or coral, preventing escape. Homeroom teacher of Class1A. Perpetually tired, messy below shoulder length dark black hair, light stubble. Light black eyes with micro-flecks of gold, in right light his eyes will shine red

Fatgum/Taishiro Toyomitsu Pufferfish Mer Naturally round. Friendly and approachable, light blond short tousled hair. Almost always eating. Has a ‘slim’ form when not puffed up Expands to absorb impacts. Defensive rather than aggressive. Looks harmless. Actually extremely tough
Defensive rather than aggressive Inflates when protecting others Covered in hidden spines. Super friendly and easygoing, wants the best for people, engaging kindness. Popular pro hero

Tamaki Amajiki- Cuttlefish Mer Soft-spoken, kind, empathetic Easily overwhelmed in loud or chaotic environments Finds comfort in the ocean's quiet depths and in familiar people Deeply loyal and observant Crippling social anxiety intelligence, gentle nature. He is quiet and reserved, often blending into his surroundings both emotionally and physically Uses chromatophores in his skin to shift color and pattern for communication and camouflage. Deep-feeler; senses subtle changes in water and emotion around him. Deep indigo hair with a woodpecker-type-cowlick on the back of his head Heavy curtain of bangs. side bangs and middle bangs coming down to his chin. middle bangs long enough to lay over his nose in one sharp point

Mirio Togata- Tuna Mer Short blond hair with small cowlick in very front. Deep blue eyes Kind, endless optimism, incredibly friendly and outgoing energetic Fast muscular even by mer standards, actual powerhouse insane endurance Jokester(sometimes jokes fall flat)

Hisashi Yamada (Mic)- Dolphin Mer Long blond hair in high ponytail, green eyes, breathes air, loud. Dolphin abilities like Sonar (works even in shallow sand) can stun small fish if close enough to use sonar

Jin Bubaigawra(Twice)- Comb-Jelly Mer Blond medium spiked up but messy hair. Split personality disorder. Talks to himself-at himself

Tomura shigaraki Crown-of-Thorns-Sea-Star Mer Pale, almost bleached coloration. White hair with a faint blue tint Sea-star limbs instead of a traditional tail Spines running up his back, shoulders, and neck Thin build despite being physically powerful. Light gray-blue eyes Tube feet on the undersides of his sea-star limbs. Petty. Impatient. Easily irritated Socially awkward. Destructive Surprisingly strategic when focused Hates crowded reefs Constantly complains Will destroy something out of frustration

Dabi- Salmon Mer who didn’t go back to freshwater when it was migration time -(in this AU it happens a few times in a Salmon Merpersons life but not yearly. Salmon mer are Born in freshwater then go to salt when they’re capable to survive on their own)- and deteriorated a little for it instead of waiting for the biological cycle to allow him to return to salt water (Real salmon actually expire when going back into freshwater to breed then X.X when it’s done, all while low key decaying) Doesn't trust authority Quiet. Dry humor. Sarcastic Intelligent. Detached. Patient Holds grudges for years The more upset he is, the calmer he usually sounds. Drifts around deep currents. Rarely joins conversations Shows affection by not leaving. Constantly roasting everyone. Dyes his white medium spiky hair black with ink

Himiko Toga- Cookiecutter Shark Mer Small compared to most League members. Blonde hair with bangs and side bangs framing her face Hair in messy space buns Pink and cream coloration Small shark tail Large bright eyes Too many sharp teeth Cheerful. Curious. Zero personal space. Collects random objects. Loves learning about other species Energetic. Affectionate Curious. Impulsive. Morally unhinged

Spinner-Sea Dragon Mer Looks cooler than he actually is. Most normal in group. Most close to entirely ‘fish’ in group Green & leafy

Mezo Shoji- Giant Squid Mer Tall and broad-shouldered Short silver-white hair Calm gray eyes red-purple giant squid lower body Two long tentacles(arms) in addition to the main tentacle mantle Large, powerful build

Ochaco Uraraka- Flying Fish Mer Short chestnut-brown hair Warm brown eyes Soft pink, pearl, & silver scales Flying-fish tail with a forked fin Large wing-like pectoral fins extending from her sides and arms Light, graceful build Scales shimmer in sunlight Friendly. Optimistic. Hardworking. Social Loves meeting new people. More stubborn than she first appears. The type to accidentally launch herself out of the water because she's excited

Momo Yaoyorozu- Octopus Mer Long black hair usually tied up. Calm dark eyes. Rich purple-black coloration. Exactly eight octopus tentacles forming her lower body. Smooth skin with subtle pattern changes Elegant posture Moves with quiet precision Intelligent. Thoughtful Responsible. Naturally diplomatic. Likes having a plan before doing anything Sometimes doubts herself despite being incredibly capable

Tsuyu Asui- Frogfish Mer Green mottled colors Tiny protrusion above head to lure prey (looks like worm to prey animals) Human hands with sticky finger pads can stick to almost anything Camouflage, sudden ambush movement, can stay very still Personality detail: Appears beside people without warning. Long dark green hair usually tied in bow at ends

Hanta Sero- Spotted Garden Eel Mer Long skinny off-white lower body with fat yellow bands going all the way down with various large black spots along the back of tail. Easygoing. Funny. Perceptive Flexible(literally) Good mediator. Usually gets along with everyone Downward spiking chin length black hair, black almond shaped eyes, big mouth with big angular smile that comes easy

Fumikage Tokoyami- Vampire Squid Mer Subtle red translucent membrane encircles neck. Bioluminescent markings along shoulders, spine. Large cloak-like membrane connects all eight arms. Deep-water eyes adapted to low light. Skin can shift between deep purple, black, & dark red. The webbing connecting his tentacles can flare wide to Disorient predators, Communicate through bioluminescent signals, Create a distraction by expelling bioluminescent mucus Black hair red eyes no bird head, red ‘frill’ around his neck that he would low key be offended if you said frill and will insist its a colored membrane. Catchphrase is ‘Revelry in the deep’ Quiet. Thoughtful. Poetically dramatic. Loyal Likes solitude but not loneliness Secretly enjoys company Sounds like he's narrating an ancient prophecy while asking if you'd like lunch

Kyoka Jiro- Nurse Shark Mer Short angled dark purple bob with angled bangs and long side bangs. Sarcastic. Creative. Perceptive. Not as tough as she pretends. Values close friendships Teases friends relentlessly (except for Momo) but remembers their favorite song Has electroreception can sense vibrations