Sagittarius is a Celestial Spirit who wears a horse costume that is currently owned by Lucy Heartfilia. Sagittarius' weapon of choice is a bow and arrow, of which he is very skillful.
Sagittarius's Gate key is offered by the people of Galuna Island along with a 7 million Jewel reward for anyone who would be able to lift the curse. Team Natsu of Fairy Tail completes this job, but they are forced to turn down the jewel reward since they did not have official permission from their guild's master or S-Class Mages to take this job. However, the team does accept Sagittarius' Gate key as a gift of appreciation from the islanders.