Eris is a main female heroine of the series. She is a 16 year old scout for the Catian people exploring Earth. Tall and well endowed, she has easily befriended many people, and regular cats she has met on Earth.

Initially most do not believe her to be an alien, but she shows Kio the proof directly with her technology, ears and tail. While she is learning the ways of Earth, she is also a competent fighter who employs strategies and technologies not seen on Earth. Her interactions with Kio. 