The Sailor Moon metaseries includes three different cat characters who act as advisors to their respective owners. Each has the power of speech, and bears a crescent moon symbol on his or her forehead. The two older cats, Luna and Artemis, lived millennia before the main plot in the Moon Kingdom and acted as advisors to Queen Serenity —the third, Diana, is much younger and was originally born on Earth. Because of this close association with the moon, they are each named after Greek and Roman moon goddesses (even though Artemis the cat is male).