Board Thread:Archived Breeding/@comment-5.67.133.185-20130622140033/@comment-112.198.79.141-20130625130956

The best way to get a plankton dragon is a level 10 Terra and level 10 Sea pairing. The results of that can be Plankton, Mud, or Waterfall. Since Mud and Waterfall are both 1 minute breeding and 1 minute hatching times, you will generally get the Plankton (20 hour breeding/hatching) within a few minutes of starting.