Kas was a Klingon ambassador who attended and spoke at a peace conference between the Klingon Empire and the Federation in 2409. He was a staunch opponent of the Federation-Klingon War after an instance in which he and the crew of a civilian vessel were saved by the USS Leviathan.
In 2405, a Klingon civilian vessel on which Kas was a passenger was besieged by pirates. The USS Leviathan, under the command of Captain Masc Taggart, assisted the Klingons despite being at war with the Empire. Some of Taggart's crew thought of staging a mutiny, but his senior staff remained loyal, and as a result of their assistance, Kas became a strong proponent to ending the war thereafter.
- Star Trek: Federation Legacy – "The Kuvah'Magh" (First appearance)
- Star Trek: Federation Legacy – "The Doomsday Device" (Mentioned only)