Characters from Doraemon: Nobita's Great Battle of the Mermaid King
Princess Sofia
- Awesome Moment of Crowning: The film ends with her coronation as Queen Sophia of Aquaria.
- Bathtub Mermaid: Subverted; her first day hanging out with Nobita and gang have Sophia passing out due to lack of water, until she recovers after submerging herself in Shizuka's tub. But she's still in her human form through and through.
- A Child Shall Lead Them: By the end of the movie, she becomes the youngest queen of Planet Aqua.
- Cool Crown: Her bejewelled tiara - the Headband variation - which she wears in her earlier scenes before lending it to Shizuka after the latter shows interest in it. It's later revealed to be the long-lost "Mermaid Sword", transforming after Sophia prayed to Manatia for help in saving her kingdom.
- Dark and Troubled Past: She lose her manga-only Mother, Father, and Grandfather to Bulkin's war when she was a baby, and must face the responsibilities of being a leader to her people since a young age.
- Fish out of Water: When she arrives in Tokyo for the first time and is visibly confused over her surroundings, from nearly getting hit by a car to getting curious when seeing an airplane for the first time and exclaiming, "It swims through the air!"
- Identical Grandson: Her earlier ancestor, The Original Sophia from 5000 years ago, looks a lot like herself and she has the same name as her present counterpart princess.
- Mermaid Arc Emergence: Sophia's bath scene in the anime when she flips her hair out when emerging, a reference to Ariel from The Little Mermaid.
- Modest Royalty: She's a princess (later a queen) but seems to prefer her Casual attire over her court gown.
- Nice Girl: Friendly, affable, polite despite being a princess, and easily becomes besties with Shizuka, even offering Shizuka her tiara when the latter wonders "How it's like to be a princess". Sadly her niceness would lead to the next trope.
- Nice Job Breaking It, Hero: Sophia offering Shizuka her tiara would result in Tragis - who's after Sophia's trail - abducting Shizuka, mistaking her as the real princess.
- Our Mermaids Are Different: Sophia, like the rest of her fellow merpeople, started off as humans before getting adapted to living underwater. And unlike most media depictions of merfolk, her kind transform into merpeople by touching a knob on their enchanted outfits, turning their lower bodies into tails.
- Sirens Are Mermaids: She sings at the beginning of the 30th movie underwater.
- Spell My Name With An S: Is it Sophia or Sofia?
- Spoiled Sweet: A princess who's kind, friendly, and cares for her allies.
- Vague Age: She seems to be at the same age as Nobita and his friends.
Haribo
The leader of the Aquarian merpeople army, and a sentient pufferfish-boy who's the bodyguard for ensuring Princess Sophia's safety.
- Mister Big: He's barely the size of a human child, and a commander and enforcer of the merpeople army.
- Fantastic Racism: His dislike for surface folk is quite evident when upon meeting Sophia and the gang, he immediately orders them arrested for "kidnapping the Princess" and sentences them to be fed to a Megalodon. He mellows out a bit later on.
- The Napoleon: He's one of the smallest characters, and yet doesn't hesitate to boss his army around as he's their general, including on Doraemon and gang after making it clear to them that he's in charge.
- Painful Pointy Pufferfish: A sentient humanoid / merpeople version of the trope. Who likes using the spikes atop his head for jabbing and headbutting foes.
- Reused Character Design: He appears to be modified from Kibo's template appearance-wise, sharing the same oversized head that takes up half his body, shaggy unkempt hairstyle, and tiny feet (in humanoid form after ditching his merman form) in shoes that couldn't possibly fit him.
- Too Many Halves: A half-pufferfish, half-human, half-merman hybrid?
- Use Your Head: His favoured move against opponents is by headbutting them in the rump, doing this to Doraemon when they first met, and on Nobita later on as well as a random enemy mook in the finale. Also, being a pufferfish, his hair are spikes.
The Villains
Bulkin
The all-powerful merman warlord who rules over the Demon Fish Tribe, Bulkin seeks the Mermaid Sword for it's powers to make him the conqueror of the oceans.
- Adaptation Species Change: He looks far more human-like in the anime than the manga, save for the colour of his skin.
- And I Must Scream: His eventual fate. Getting sucked into the Underwater Pump Simulator to be sealed forever can't be a good way to go...
- Authority Equals Asskicking: As the leader of the Demon Fish Tribe, it goes without saying he's their most powerful champion.
- Beard of Evil: Sports quite a magnificent bushy beard. It's even larger and scarier-looking in the manga.
- Big Bad: The main villain of the movie whose minions are enslaving entire worlds, who covets the Mermaid Sword for conquering the seas.
- Black Knight: He's clad entirely in jet-black armour and is the leader of the violent mermen conqueror clan.
- Dark Is Evil: His attire is entirely in black, which makes it really clear that he's in charge of the Demon Fish Tribe.
- Fish People: In the manga only, where he have more fish-like features on him.
- Large and in Charge: He towers over his lesser soldiers in the Demon Fish Tribe, and it's made quite clear he's their boss.
- Making a Splash: Once he got his hands on the Mermaid Sword, he can unleash tidal waves, tsunamis, thunder storms, and have power over the seas.
- Never Bareheaded: We never get to see what his true face looks under his helm.
- Obviously Evil: Horned helmet? Dark armour? Scary-looking fangs? Ruthless conqueror of worlds? Check, check, and check.
- Too Clever by Half: What ultimately leads to his defeat - he's invincible and unstoppable with the Mermaid Sword in his hands, but he never considered his weapons' weakness on land. And then the heroes managed to trick him to take the fight on a beach with the Simulator, turning the tide of battle altogether.
- Villain Opening Scene: He's introduced in the very first scene of the movie, ordering his minions to wipe out the inhabitants of a neighbouring planet with his war machines. Said planet seems to be primitive and lacks any defenses against Bulkin's war machines, and he takes glee ordering the massacre and destruction. Then cuts to Suneo bragging his holidays to the gang immediately after.
Tragis
- Adapted Out / Canon Foreigner: He doesn't have a counterpart in the manga.
- The Dragon: The second-in-command to Bulkin and his army.
- I Lied: After getting the fake Mermaid Sword, he renege his promise of releasing the heroes, telling his men to do whatever they want to them - knowing full well his minions are ready to execute children.
- Mook Lieutenant: Leads the lesser minions in battles.
- Never Bareheaded: Like his boss, his true face under his helmet is never seen.
- Satellite Character: All his scenes are interactions with his boss, Bulkin, and he's barely fleshed out with any characteristics other than "minion".
- Would Hurt a Child: He would execute Shizuka after finding out he got the wrong princess, and gleefully puts her through Electric Torture to taunt Nobita and Doraemon out of hiding.
