Aquarius

Aquarius "The Water Bearer" is a Celestial Spirit that is one of the 12 Golden Zodiac Keys. Her key is currently owned by Lucy Heartfilia.

Appearance
Aquarius is a mermaid-like Celestial Spirit. She has a long blue tail, large breasts and she wears a revealing bikini top. She has two gold armlets and she wears a jewel circlet. She wields an urn which is the basis of her powers.She was designed to have her appearance correspond with her respective zodiac sign whereby "Aquarius" is depicted as a merman or mermaid carrying a vessel from which is pouring a stream of water as reflected by the urn and water magic Aquarius uses in the Fairy Tail series.

Personality
Aquarius is a very moody and ill tempered woman who often threatens to kill her owner, Lucy. One of the most important distinctions between Aquarius and the other Celestial Spirits is that while the other spirits serve Lucy obediently, Aquarius is irritated by her. Whenever she is summoned, depending on her mood she will either attack the opponent, Lucy, or both. The risk of summoning her is great because Lucy has said several times she is her most powerful Celestial Spirit. Despite this, she does care for Lucy's safety. She is very kind and loving towards her boyfriend, Scorpio, to which she shows a completely different side of herself. She also goes as far as to threaten Lucy to keep quiet about her moodiness in front of Scorpio unless she wants to be a "drowned corpse". Despite all this, Aquarius has helped Lucy out several times over the course of the series.

History
Aquarius's previous master had been Lucy's mother, Layla Heartfilia. When Layla retired from her work as a Mage, she entrusted the key to another Mage with instructions to present Aquarius's key to Lucy should Lucy decide to become a Mage.

Macao arc
As Natsu Dragneel fights Bora, Lucy summons Aquarius to send Bora's ship full of captured girls to the harbor. Happy shows a friendly interest in her given that she was a fish, to which she doesn't respond to. After doing her job, she states her desire is to not be bothered for a week as her boyfriend is taking her on a vacation. Before she leaves, she rubs it into Lucy's face that she has a boyfriend while Lucy doesn't.

Galuna Island arc
Aquarius is re-summoned when Lucy battles Sherry to deal with Sherry's Doll Play Magic. Sherry notes that Aquarius is a powerful spirit and and gains control of Aquarius. Aquarius attacks Sherry along with Lucy because she didn't like being controlled. Before leaving, Aquarius berates Lucy's personality claiming that it's the reason she hasn't and will never get a boyfriend like she has.

Phantom Lord arc
It is mentioned by Lucy that Aquarius gave her a very painful punishment (spanking) for losing her keys after she was kidnapped by the members of Element 4.

Loke arc
Aquarius is summoned briefly along with all of the rest of Lucy's spirits when they are confronted by the Celestial Spirit King.

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 Aquarius through Juvia. Aquarius attacks everyone and Juvia and Lucy join hands to use Unison Raid. After defeating Vidaldus with this, Aquarius mouths off at Lucy, saying that she shouldn't ever summon her in such a strange place or she'll kill her, even wondering if Lucy will summon her next from inside a toilet bowl. She leaves again, saying not to summon her for two weeks and commenting that Lucy should get a boyfriend.

Oración Seis arc
Lucy summons Aquarius as her strongest Celestial Spirit in her battle against Angel, especially since the battle is taking place at a river. Desperate to defeat Angel, Lucy tells Aquarius that she's free to do anything, including attack Lucy, so long as Angel is defeated. Aquarius agrees, but is removed from the battle when Angel summons Scorpio, who is revealed to be Aquarius's boyfriend, something that Angel was aware of but Lucy was not. The Celestial Spirits go off on a date with consent from Angel, much to Lucy's dismay.

Edolas arc
After Hughes dumps both Natsu and Lucy into a pond after using Hell Coaster, Lucy summons Aquarius to fight Hughes. Aquarius tries to attack Hughes; however, Aquarius is shocked to realize she cannot control the water because Hughes is controlling it. Hughes then sends her attack back at her and she screams for Lucy to take cover.

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, and comments 'distracting men with bathing suits, you still have such a long way to go'. She doesn't pick on her usual victim, Lucy; instead, she chooses to bicker with Cana, saying all women are her enemies and that just being 'firm and bouncy' doesn't count as 'justice'. Aquarius also gives Cana zero points as a woman. Through this argument, Lucy takes note of how similar Cana and Aquarius are.

X791 arc
She is seen celebrating Lucy and her friend's return from the timeskip in the Celestial Realm, saying that bringing them there is a special case. Later on, she is seen talking to Juvia and noting that Juvia was the one who once shared a body with Lucy then asking her if she has a boyfriend, causing Juvia to blush then answer 'no', then asking her if Juvia wants to become like Lucy. When Lyra was singing a song, she is seen getting along with Juvia. Before Lucy and her friends go back, she is talking to Juvia while holding her hands and Charle commenting that they seem to become good friends.

Magic and Abilities
Water Magic: Aquarius uses Water Magic as her primary source of combat. She is a powerful Celestial Spirit; even after Loke became one of Lucy Heartfilia's Celestial Spirits, Lucy still considers Aquarius on the same level as him or even above.
 * Giant Wave Attack: An unnamed 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.

Immortality: As a Celestial Spirit, Aquarius cannot die unless she is forced to stay in the Human World somehow.

Major Battles

 * Natsu Dragneel, Lucy Heartfilia (owner), & Happy vs. Bora
 * Lucy Heartfilia (owner) vs. Sherry Blendi
 * Lucy Heartfilia (owner) & Juvia Lockser vs. Vidaldus Taka
 * Lucy Heartfilia (owner) vs. Angel
 * Natsu Dragneel & Lucy Heartfilia (owner) vs. Hughes & Byro
 * Lucy Heartfilia (owner) & Cana Alberona vs. Freed Justine & Bickslow

Trivia

 * Lucy's quote when summoning her is: "Open the Gate of the Water Bearer! Aquarius!"
 * She was originally only able to be summoned by Lucy on Wednesdays.