The "Guardian Cosmos" is a very mysterious and little known sprite. Some refer to her as the "Cauldren Guardian." Cosmos wears an outfit that is beautifully designed and poofs out by the legs and she also carries a staff. The Guardian Cosmos is the guardian of the cauldren and is seen only briefly in the manga. In the manga, Cosmos tells sailor moon that she, too, once had a starseed as big as Sailor Moon's. She asks the sailors if they want to become immortal or to simply be returned to their normal forms. Sailor Moon thanks Cosmos for the offer to be immortal, but says no, and with one blast, the Guardian Cosmos sends the senshi back. After the blast, Sailor Moon looks at Cosmos and says, "That's... Choas!" There is debate over this, but so far I haven't found out officially if she is Choas or not. Only Naoko Takeuchi knows. :D