Luna- Luna is the cat guardian of Sailor Moon. Luna is black with a crescent moon on her forehead. She was rescued by Usagi and Luna told Usagi that she was Sailor Moon. Luna is more of a babysitter to Usagi at first, but as she matures, Luna's role changed to more of a guardian. She was constantly shaping up Usagi to be the pretty suited girl in the sailor fuku. In the Sailor Moon S movie, Luna was briefly transformed into a human to be with a human she fell in love with a human named Kakeru.
Artemis- Artemis is the second guardian cat. He is white with a crescent moon on his forehead. He is the guardian of Sailor Venus. Artemis is usually picked on by Luna and the others, being the only male in the group. He was also the voice of central control that Luna was going to for advice, until Luna discovered his plot.
Diana- Diana is the last guardian cat. She is the daughter of Artemis and Luna, though Artemis didn't know that at first, and Luna was furious about it. She appeared in the Supers series and went back to the future with Chibiusa in the Sailor Stars series. Diana is a light gray, with a tint of pink. Diana is the guardian cat of Chibiusa after the Luna-P ball.