they are from the same planet as Sailor Lead Crow and are the pets/care takers to Rei (Princess Mars) they are two crows that are always at the temple and take food from Rei they dont show up in the anime as much as the manga but when they do its in a time of need. in the episode where Rei finds out she is Sailor Mars her and Usagi get caught in another dimension Phobos & Deimos bring her a sacred arrow which hurts the Yoman and allows her and Usagi to Henshin