Neptunia is a mutated humanoid fish out to protect her home against the actions of land-dwellers. To this end, she is in command of all ocean life, or at least what swims around in the vicinity of her home. Due to the traumatizing circumstances of her acquiring a new identity, Neptunia started out hostile — but not irrational — towards the land-based population. After an encounter with Darkwing Duck, and more importantly Launchpad McQuack and Gosalyn Mallard, Neptunia mended her ways to seek cooperation with the land and even became a protector of St. Canard as a member of the Justice Ducks. Her main tools are a trident and a trumpet that enables her to get orders across to her soldiers over a great distance. Outside the role of commander, she relies on her impressive strength as well as her ability to live both in water and on land, provided she stays hydrated.
She is voiced by Susan Silo.
Neptunia began life as a normal fish, possibly a halibut, and she was still very young when she mistook a sinking canister of radioactive waste for another fish. Soon, she was trapped within a shower of them and got a full dose of whatever it was that was being dumped. It changed her into a unique creature, but at the cost of her sense of identity. Unwilling to let another suffer what she went through, Neptunia organized her fellow ocean inhabitants into a force that could fight back against pollution. Neptunia became their leader in the process. Though never unreasonable to individuals, her initial strategies did not include the well-being of the population of St. Canard at large. As she was busy flooding St. Canard and thereby taking people drowning for granted, Launchpad McQuack talked her out of it, playing into her care for others to not make victims. She relented and formed a friendship with him, Darkwing Duck, and Gosalyn Mallard in the process. This friendship formed the basis of her recruitment later on into the Justice Ducks when the Fearsome Five took control of St. Canard. While establishing good ties with fellow mutant Stegmutt and fellow woman Morgana Macawber, Neptunia, as mistress of the waters, found a designated enemy in the Liquidator, the self-proclaimed master of all water.
As ruler of the ocean, Neptunia has a lot of fishes and other water-born lifeforms under her command, such as whales, starfishes, octopi, crabs, swordfishes, electric eels, and lobsters, who perform all kinds of jobs for her. Neptunia is fluent in English and fish languages, but as her voice only carries over a limited distance, she has fashioned a trumpet from a shell to get her orders out further or to multiple allies at once. When having to work alone, Neptunia counts on her physical strength that borders on superhuman power. Whether she goes barehanded, carrying her trident, or utilizing a makeshift weapon, her short stature belies the punch she packs. Her mutation furthermore has granted her the possibility to breathe out of water, although her land durability remains limited by the length of time she can keep her scales moist. Because she's capable of living in both environments, she has constructed her base so that it accommodates to land-dwellers would she have them over.
Under no definition is Neptunia a bad person, but life after her mutation has been a continuous fight with limited success for some understanding from the people who put her through that. As a result, Neptunia has become bitter, irritable, and short-tempered, going at her mission to save her home with no-nonsense aggression. The caring and even flirtatious woman underneath the cynical and condescending exterior occasionally shines through to provide a fair warning or to reach out to land-dwellers, but just as easily she is shut away when the reaction is not what she hoped for. Due to ongoing disappointments, positive reactions have little influence on her until she is convinced of the speaker's good intentions. If that can be accomplished, she is an acquaintance to be counted on no matter what initial impressions she may cultivate. When it comes to ocean life, Neptunia is more open to social connections. If any of her troops are harmed, she personally goes after the perpetrator and she never asks anything that she can do herself, hence why she has their trust and loyalty.
Neptunia is a turquoise humanoid fish with flippers for feet, two pink fins on her head, and pink lips. She wears a formfitting green suit over which her trumpet rests from her right shoulder on her back.
- Neptunia is named after Neptune, the Roman god of the seas. Her trident also is a reference to him, as it is one of Neptune's attributes. The trumpet, on the other hand, is a reference to Triton, another sea god.
- In terms of superheroes, Neptunia fuses traits of Aquaman and Namor.