Sailor Mau

Sailor Mau is the Sailor Senshi of the planet "Mau", the homeworld of Luna, Artemis, Diana, & Tin Nyanko. Though Sailor Mau-herself never appeared in the manga, it's implied that Sailor Tin Nyanko killed her in order to get her star seed and gain Sailor Galaxia's favor. Luna and Artemis holds a personal grudge against her for killing Sailor Mau, after having learned of the fact.

She is mentioned in "Act 54: Stars 5", by Kou Yaten (Sailor Star Healer's human guise), along with Sailors' Chū (the Sailor Senshi of Iron Mouse's homeworld), Mermaid (the Sailor Senshi of Aluminium Siren's homeworld), and Coronis (the Sailor Senshi of Lead Crow's homeworld).

Information
In the first anime series, it was revealed that Sailor Tin Nyanko was originally a good Sailor Senshi, hence, she is believed to have been the original "Sailor Mau."

Trivia

 * The name 'Mau' come from "mau", one of the photonic of the sound made by cats (the other being "nyan"). It also comes from the name of a rare breed of cat, the "Egyptian Mau".

Gallery
Sailor Miaou Sailor Mau Sailor Mau