Scorpio

Scorpio is a Celestial Spirit that is one of the 12 Golden Zodiac Keys. His key is currently owned by Lucy. He is also Aquarius's boyfriend with which he has a happy relationship. His weapon appears to be a large, strange gun shaped like a scorpion's tail.

Oración Seis arc
Angel summons Scorpio in her fight with Lucy Heartfilia as a means of preventing Lucy from using her Celestial Spirits. Upon arriving, he is greeted by Aquarius, who appears very happy to see him. Scorpio politely introduces himself to Lucy since she is Aquarius's master and instead of attacking her, he leaves with Aquarius to go on a date. After her defeat, Angel is arrested, breaking her contracts with her spirits. Scorpio, along with Aries and Gemini, sought out Lucy and form contracts with her instead.

Trivia

 * Scorpio has a strange manner of speaking which is similar to the third person. He says "We are" in the beginning of each sentence.
 * The word 'Antares' is written on his tail. Antares is the brightest star in the Scorpio constellation.