Yamata-no-orochi translates from the
Japanese as
The Serene Dragon. However,
something appears to have been lost in the
translation, as it and its Eastern Dragon kin are reputably
vicious and consider terrorizing entire towns just good clean fun. However, much to the likely relief of contemporary Japanese, these dragons have held no power since about 700
CE, and have been reduced to
weevil eaters.
Yamata-no-orochi's distinguishing characteristics were eight heads and eight tails, though 'yamata' can mean 'many' as well, so it is possible the dragon possessed more. In accord with the number of its appendages, it is said to have been large enough to stretch over eight (or more) valleys and hills.
If Yamata-no-orochi's size was not a dead giveaway to the casual observer, red eyes and a covering of shrubbery in place of fur might have sealed the ID. Yamato-no-orochi, not unlike some contemporary villains and cinematographers, had a taste for virgin flesh, and considered an unconsummated lass a tasty snack.
Legends are unanimous in crediting Yamata-no-orochi's demise to one Susanoo (Susanowo, Susano, Susano-o), who killed him by empolying one of a variety of possible subterfuges, most of which involve intoxicating the dragon. In some versions of the tale, Susanoo was unable to cut off the last of Yamata-no-orochi's eight tails, and in determining the reason for his failure, discovered the magic sword Kusanagi no Tsurugi ("The Grass-Cutting Sword"), now considered a National Treasure of Japan.
An enjoyable retelling of this myth can be found at http://www.joho-shimane.or.jp/cc/sic/8-0/98autumn/mytholog.htm
An encyclopedic retelling is available at
http://www.blackdrago.com/famous_japanese.htm#yamata