A slightly more detailed list:
  • Storm Dragon: Trapped in chest in Mt. Zozo; it's fairly difficult to miss.
  • Blue Dragon: In the secret room of the Ancient Castle
  • Dirt Dragon: Pull the lever (the third one I think) to drop onto the stage in the Opera House
  • Red Dragon: In the Phoenix Cave; it's also fairly difficult to miss
  • Ice Dragon: The Narshe snowfields (the same place where you split into groups and fought Kefka in the World of Ruin)
  • White Dragon: Several floors up in the Fanatic's Tower, in one of the rooms; almost impossible to miss.
  • Gold Dragon:
  • Skull Dragon: Both are in Kefka's tower and are pretty hard to miss. If I'm not mistaken, you fight one with group one and one with group two.