The Sarcophagus, or Ship of the Dead, was a 23rd century Klingon ship from the House of T'Kuvma that included the remains of fallen Klingons on its outer hull. The ship also featured new technology which made the ship invisible to Federation ships. 

General Kol took control of the ship following the death of T'Kuvma in order to share the invisibility screen technology with other Klingon houses.