Pragine 63 was a planet located on the edge of Klingon space. It was inhabited by the intelligent Calations.
In the mid-23rd century, the Calation civilization was on the brink of starvation. The Federation assigned the USS Cabot to intervene without alerting the Klingons. Unfortunately, two weeks later genetically-engineered tribbles that had escaped containment on the Cabot found their way to the surface and overwhelmed the planetary environment, forcing the evacuation of the entire civilization. (ST: "The Trouble with Edward")