A Klingon D-7 class battle cruiser, the I.K.S. Klothos was under the command of Captain Kor in 2269. That same year, the Klothos was trapped temporarily in the extradimensional realm of Elysia, an alternate universe in which a veritable graveyard of space vessels from countless worlds had accumulated over the centuries. With the help of the crew of the U.S.S. Enterprise, Kor and his crew managed to get the Klothos free and return to normal space on stardate 5267.6 (2269).
Kor later commanded this ship during the Klingon victory over the Federation at Caleb IV.