A Klingon campaign in the late 23rd century in which warriors hunted tribbles across the galaxy and an armada destroyed the tribble homeworld, leaving the species thought extinct.
Klingons and tribbles react to one another with mutual loathing, as the Original Series episode The Trouble with Tribbles shows. The Empire came to see the fast-breeding creatures as an ecological menace and a mortal enemy.
Worf tells the story in the Deep Space Nine episode Trials and Tribble-ations. Hundreds of warriors were sent to track the animals down wherever they had spread, and a fleet obliterated their home planet. By the end of the 23rd century they were gone. Odo is unimpressed by this piece of Klingon glory.
The victory was undone in 2373. When the crew of the Defiant returned from their trip to Station K-7 in the past, tribbles came back with them and were soon filling Deep Space 9.