Luna is the advisor to Sailor Moon as well as her cat. Her fur is black, excluding a crescent-shaped spot on her forehead. She is a sentient and sapient creature with certain magical abilities, one of which allows her to speak verbally.
Since her memory is restored to a greater extent than those of her team mates she often is able to provide insights in motivations and backgrounds of friends and foes alike. This, coupled with her responsible nature, makes Luna a respected authority in the team.