K'mtar was an alias adopted by a future version of Alexander Rozhenko. In this alternate future, Worf was assassinated by political enemies, and Alexander, who had become a diplomat, was unable to save him. He decided to travel to the past (2370), and faked an assasination attempt on the Worf of that time, leaving evidence framing the House of Duras. Alexander then adopted the identity of K'mtar, gin'tak to the House of Mogh. He hoped that Worf would be sufficiently worried by the assassination attempt to send the young Alexander to a Klingon military academy, thus enabling him to protect his father in the future. (TNG: "Firstborn")
- K'mtar (or the adult Alexander) was played by James Sloyan.