IKS T'Acog

From Memory Alpha, the free Star Trek reference.

The IKS T'Acog was a Klingon cruiser in service during the 24th century. In 2364, the T'Acog was sent to apprehend the Klingon criminals Korris, Konmel, and Kunivas, who had commandeered the Talarian freighter Batris. By feigning a power failure, the fugitives were able to lure the T'Acog into close range, and then destroy it with a barrage of merculite rockets when the cruiser lowered its shields to board the freighter. There were no survivors. (TNG: "Heart of Glory")

According to the Star Trek Encyclopedia, the T'Acog was a K't'inga-class battle cruiser. In the episode, it was referred to, simply, as a "cruiser".