Iota Geminorum IV

From Memory Alpha, the free Star Trek reference.

Iota Geminorum IV is the fourth planet in the Iota Geminorum star system and the homeworld of the tribble. Reptiles are the natural predators of tribbles on this world, and are known to keep the tribble population in check, which when removed to other environments breed uncontrollably. (ENT: "The Breach")

In order to fulfill their self-given task to hunt the tribble species to extinction, the Klingons presumably bombed Iota Geminorum IV in the late 23rd century, which suggests it might now be a part of the Klingon Empire. (DS9: "Trials and Tribble-ations")

This information is not from dialog, but originated on a background graphic in Keiko O'Brien's schoolroom on Deep Space 9, first seen in DS9: "The Nagus".