Lyra
Lyra is a Celestial Sprit summoned by Lucy Heartfillia. First summoned in Episode 12, she is a singer and a harp player whose songs reflect the heart and feelings of those who listen. Lyra is also very well versed in the ways of magic and can only be summoned by Lucy three days a month according to their contract. (Source: Fairy Tail Wikia)
Pictures
Mangaography