Tso'Bok was a Klingon male who served as a doctor in Starfleet during the 25th century. As of 2416, he held the rank of Commander, and was chief medical officer aboard the USS Skyfall. (Star Trek: Sons of Liberty: "For I Dipt Into the Future...") He was born on Sherman's Planet in 2385, the son of Klingon expatriates. While attending secondary school, he befriended human colonist Tristan Sinclair, and the two would remain close for the remainder of their lives. After Skyfall's destruction, Tso'Bok was reassigned to the USS Ulysses.