Before the Crystal Millienium, even before the Silver Millienium, there is a legend about the eight dragon spirits that dewelled inside each planet. Their abilties corrosponded with each of the former senshi's powers (i.e. Rei/ Sailor Mars had the power of fire) In fact the dragons recieved their powers from the Sailor Scouts. (In one episode, Sailor Jupiter summons her dragon: Jupiter Thunder Dragon) They remained dormant inside their planets untill after the Silver shield had been destoryed (even Sailor Pluto had her doubts about them). Freed, the dragons escaped to times and places unknowned. Some of them were found by either the other Sailor Scouts, or by the Nega-Rebels, and were taken care of. Tiamat, Saturn's dragon, was captured by the Nega-Rebels and was sent to dispatch of the other dragons. Leviathan (Neptune's dragon) escaped to Drecia (the planet looked like a swampland and has buildings found in Anchient Greece when he arrived. Leviathan established himself as the God of the Seas. Accidently, a young female Caller summoned him,a nd the rest as they say, is history. Ea, Venus's dragon, escaped to Drecia's future, where she was transformed into dragonite, and then into Crystallyne. Kirin and the other children of the surviving dragons are known as the Senshi No Ryuu (AKA the Dragon Scouts).

The Dragon Scouts have the ability to transform into dragons. Sometimes they're conscience of it, most times they're not.