Aquarius, "The Water Bearer" (アクエリアス Akueriasu) is a Celestial Spirit that is one of the 12 Golden Zodiac Keys. Her key was owned by Lucy Heartfilia until she sacrificed it in order to summon the Celestial Spirit King.
Aquarius resembles a royal blue mermaid. She has a long, blue fish-tail, light blue hair, and large bust. Aquarius wears dark blue bikini top. On each arm, she has a golden armlet and bracelet. Aquarius also has a headband, three piercings on her tail, and a golden belt at her waist. A dark blue tattoo resembling the Aquarius zodiac symbol rests on her collarbone. Aquarius also wields an urn that acts as the basis of the Water Magic she employs in battle. This design reflects her respective zodiac sign; "Aquarius" is often depicted as a merman or mermaid carrying a vessel from which a pouring stream of water emerges.
Like all the twelve spirits, Aquarius has a different form in the Eclipse Celestial Spirit Story Arc. In it Aquarius is no longer a mermaid, but instead resembles a 10 year old child. She now wears a sleeveless blue, grey, and black dress with fish scales patterns and the Aquarius Zodiac symbol on her chest. Aquarius's hair is now done up in small pigtails just above her gold headband.
Aquarius is a moody and ill-tempered Celestial Spirit who often threatens to kill her owner, Lucy. While other Celestial Spirits serve Lucy obediently, Aquarius is irritated by her. When summoned, Aquarius will either attack the opponent, Lucy, or both of them, depending on her mood. Despite this, Aquarius does care for Lucy's well-being. She is very kind and loving towards her boyfriend, Scorpio, to whom she shows a completely different side of herself. Additionally, she threatens Lucy to keep quiet about her moodiness in front of Scorpio lest Lucy become a "drowned corpse." When Lucy is in her presence, Aquarius tends to make remarks about having a boyfriend since Lucy doesn't have one. As time progresses, however, Aquarius' attitude toward Lucy becomes more lenient.
During the Eclipse Celestial Spirit Arc, Aquarius is shown to be trigger happy and much more upbeat. 
Aquarius' previous master had been Lucy's mother, Layla Heartfilia. When Layla retired from her work as a Mage because of her health problems, she entrusted Aquarius' Key to another Mage with instructions to present it to Lucy if she chose to be a Celestial Spirit Mage. Aquarius' key was the first key that Lucy ever received. Because she was young, Lucy summoned Aquarius frequently as a playmate, such as in the bath, which irritated Aquarius and began the tradition of hitting Lucy with a tidal wave. However Aquarius couldn't help but feel sorry for the girl, upon discovering Lucy didn't have any human friends to play with during her youth. 
As Natsu Dragneel fights Bora, Lucy summons Aquarius to haul Bora's ship, which is full of kidnapped girls about to be sold into slavery, towards the harbor. Happy shows a friendly interest in Aquarius as she looks like a fish but she doesn't respond about that compliment. After doing her job (and purposely washing Lucy ashore as well), she states her desire to not be bothered for a week as her boyfriend is taking her on a vacation. Before she leaves, she informs Lucy that she has a boyfriend whereas Lucy does not.
Galuna Island arc
Aquarius is called forth once more when Lucy battles Sherry, to deal with Sherry's Doll Attack. Sherry notes that Aquarius is a powerful Spirit so she gains control of Aquarius. However, Aquarius attacks Sherry along with Lucy because she does not like being controlled. Before leaving, Aquarius berates Lucy's personality, claiming that it is the reason the latter hasn't and will never get a boyfriend like she has.
Phantom Lord arc
Tower of Heaven arc
Aquarius is summoned again when Juvia Lockser is controlled by Vidaldus Taka. Juvia liquefies herself and Lucy takes advantage of the situation to summon the Spirit through Juvia. Aquarius attacks everyone as Juvia and Lucy join hands to use Unison Raid. After defeating Vidaldus with both attacks, Aquarius mouths off at Lucy, saying that Lucy should not summon her in such a strange place again, or Aquarius will kill her. She even comments if Lucy will ever summon her from a toilet bowl next time. She leaves again, saying not to summon her for two weeks and tells Lucy to get a boyfriend as usual.
Oración Seis arc
Lucy summons Aquarius in her battle against Angel, since the battle is taking place at a river. Desperate to defeat Angel, Lucy tells Aquarius that the Spirit is free to do anything, including attacking Lucy as well, as long as Angel is defeated. Aquarius agrees, but is quickly removed from the battle when Angel summons Scorpio, who is revealed to be Aquarius' boyfriend--a fact that Angel was aware of, but Lucy was not. Aquarius threatens Lucy not to say a word about her usual ill-tempered behavior to her boyfriend, or Lucy shall suffer the consequences. The two Celestial Spirits then go off on a date with Angel's permission, much to Lucy's chagrin.
After Hughes dumps both Natsu and Lucy into a pond as they rode on the Hell Coaster, Lucy summons Aquarius to fight Hughes. Aquarius tries to attack him, but then realizes that she is unable to control the water, as it is within Hughes' power. He sends Aquarius' attack back at her and she screams for Lucy to take cover of the attack.
Tenrou Island arc
While fighting Freed Justine and Bickslow, Cana Alberona uses The Prayer's Fountain card, which gives Lucy an opportunity to summon Aquarius. She angrily wave-slashes everyone as usual. However, Aquarius doesn't pick on Lucy but chooses to bicker with Cana instead, saying that all women are her enemies and that just being 'firm and bouncy' doesn't count as 'justice'. Aquarius also deems zero points for Cana as a woman. Through this argument, Lucy takes note of how similar Cana and Aquarius are.
Key of The Starry Sky arc
Note: Events in this arc occur only in the anime and do not constitute canon material.
Grand Magic Games arc
Aquarius surprises Lucy and her friends when Virgo brings them to the Celestial Spirit World for a welcome back party. During the party, Aquarius talks to Juvia, noting that Juvia was the one who once used Unison Raid with Lucy when they fought Vidaldus. Aquarius then asks her if she has a boyfriend, causing Juvia to blush and say no to her, which Aquarius concludes that she would become like Lucy. During the entire party, Aquarius accompanies Juvia and holds hands with her during the group's departure, signaling the start of a good friendship.
On the fourth day of the Grand Magic Games, Aquarius is summoned within a giant water sphere by Lucy during the Naval Battle event, declaring the water to be her playground as she prepares to attack. However, Juvia Lockser uses a spell in the water that creates a whirlpool-like effect, surprising Aquarius as she notes that Juvia's abilities are on par with her own. Observing the happenings, Aquarius declares her intentions to leave, stating that the battle won't end well. Despite Lucy telling her she's the one she can most count on in the water, Aquarius blushes and tells Lucy that she has a date and leaves, much to her summoner's annoyance.
Later on, after Uosuke defeats Pisces by using Terrain Effect: Whirlpool Zone, Lucy takes this chance to summon Aquarius. Aquarius then uses her Water Pillar spell to send Uosuke spinning through a wall. On July 7th, the Eclipse Gate is opened and in order to seal it and stop the inflow of Dragons, Lucy and Yukino summon all 12 zodiac spirits, with Aquarius among them. Aquarius is encased in an aura of Magic and flies with the other 11 spirits to the gate. Despite the attempts of the Dragons to get through, Aquarius and the other spirits, through their hard work, are successful in forcing the gate to close and repelling their attempted invasion.
After the events that transpired during the Dragon invasion, Lucy and her comrades confront the Demons of Tartarus. However, Underworld King Mard Geer uses his Curse to trap everyone within Cube, leaving Lucy as the sole human walking about. Eventually, Lucy is cornered by Jackal's explosive Curse while riding waves, promoting the former to summon Aquarius with the water in the vicinity. With three spirits summoned simultaneously, Lucy falls into the water as she begs them to defeat the Demons. Aquarius can only comment on Lucy's foolish actions.
Telling Lucy to stay back, Aquarius instantly springs into action, using her urn to summon a huge whirlpool of water that catches up Jackal, Lamy and Torafusa. As Virgo and Loke scream for Lucy to close one of the gates, Torafusa catches Aquarius off-guard by revealing that he can easily maneuver in the water, rushing at her and slicing her open with his blade-like forearms. With Jackal concurrently blasting away Virgo and Loke, Lucy is left completely defenseless, and, abandoned and bleeding on the ground, Aquarius can only watch as the three Demons approach and begin to assault her owner. However, as Jackal moves to blow Lucy up for good, Aquarius hastily pulls herself up and rushes to the Celestial Spirit Mage's aid, grabbing her and using a torrent of water to push Jackal back. Commenting that she knows none of Lucy's Spirits have the power to defeat the Tartarus members, Aquarius states that she still believes there is a way they can win: Lucy must summon the Celestial Spirit King. When Lucy questions how this is possible when the Celestial Spirit King has no key, Aquarius explains that there is only one technique for calling him: Lucy must use a substitution method by breaking one of the golden zodiac keys she has a close bond with. Shocked, Lucy cries that she would never do such a thing, though Aquarius ignores her, telling the Mage to break her key. Aquarius adds that breaking the key won't kill her, but will merely make her unable to leave the Spirit World. When Lucy refuses once again, Aquarius states that she always hated her and only put up with her because of a deep respect for Layla. Commenting that she won't miss being summoned, Aquarius screams for Lucy to step up and save her friends, and, with no other choice, Lucy tearfully raises her key. As Lucy calls forth the Celestial Spirit King and shatters the mermaid's key, Aquarius begins to weep, silently stating that though she hates Lucy, she will be sad to never meet her again. With her contract ended, she thanks Lucy for everything and returns to the Celestial Spirit World.
Magic and Abilities
Water Magic (水系各種魔法 Mizu Kei Kakushu Mahō): Aquarius uses Water Magic as her primary source of combat. Using her Magic, she is able to control water through her urn to hit opponents with great force. She is a powerful Celestial Spirit; even after Loke, a "combat specialist", became one of Lucy Heartfilia's Celestial Spirits, Lucy considers Aquarius as strong as him or possibly even above his level of strength.
- Giant Wave Attack: An attack in which she absorbs water in her urn and hurls it with tremendous force. She can throw a yacht from a few hundred miles out at sea back to shore. (Unnamed)
- Water Beam: Aquarius releases a powerful jet of water from her urn which can travel quite a distance and hit any specific target she aims at. (Unnamed)
- Bubble Shot: A stream of big bubbles are released from Aquarius's urn, which hit the opponent with great force, multiple times. (Unnamed)
- Water Pillar: Aquarius swings her urn towards the target creating a huge pillar of water that strikes the target from below. (Unnamed)
Levitation: Aquarius can float in the air.
Immortality: As a Celestial Spirit, Aquarius cannot die unless she is somehow forced to stay in the Human World.
Urn: It is a vase-like container that features curled handles that are symmetrically attached to opposite sides of the vase. It is embellished by dark blue rings studded with blue dots occupying the narrowed neck and the bottom rim of the container, with the widened center of the urn encompassed by a decorative helix-like pattern of blue stripes that are alternatively shaded. Aquarius utilizes this urn to cast her Water Magic.
Bottle During the Anime exclusive Eclipse Arc, Aquarius trades her urn in for a gold bottle slightly larger than herself. It can create powerful and fast high pressured water bullets from its spout.Cite error: Closing </ref> missing for <ref> tag.
Fairy Academy - Yankee-kun and Yankee-chan!
Aquarius appears as the harsh swimming instructor of Fairy Academy who is able to send people flying from her pool. When called by Lucy, she unleashes a great wave of water from a giant hose that flooded the whole campus, in an attempt to get rid of the students from Courage Academy.
The Exciting Ryuzetsu Land
Aquarius, along with Virgo, appears at Ryuzetsu Land swimming behind Erza and Lucy. When Lucy then asks why they came, Aquarius is quick to get angry at Lucy and sends her flying away with her water.
Fairy Tail Gekitou! Madoushi Kessen
Fairy Tail Gekitotsu! Kardia Daiseidou
- She was originally only able to be summoned by Lucy on Wednesdays.
- (To Lucy Heartfilia) "If you ever drop my key again... I will kill you!"
- (Internal monologue) "My heart... it's burning up. Even though I hated that brat, even though I hated her... I just can't stop these feelings. Never seeing you again is going to be so lonely Lucy... thank you... for everything."
Battles & Events
|No Key||Celestial Spirit King|
|Gold Keys||Aquarius • Aries • Cancer • Capricorn • Gemini • Leo • Libra • Pisces • Sagittarius • Scorpio • Taurus • Virgo|
|Silver Keys||Caelum • Crux • Deneb • Horologium • Lyra • Nikora (Nico • Plue) • Polaris • Pyxis|
|Eclipse Spirits||Aquarius • Aries • Cancer • Capricorn • Celestial Spirit King • Gemini • Leo • Libra • Ophiuchus • Pisces • Sagittarius • Scorpio • Taurus • Virgo|