|Rank:||captain, later fleet captain|
- The episode gave Garth no other name. Fan fiction has sometimes assumed that this is his surname. FASA materials refer to him as "Kelvar Leonard Garth" (FASA RPG: The Four Years War).
After a transporter accident at Antos IV, the indigenes of that world taught Garth to heal through cellular metamorphosis. This apparently drove him mad and Garth attempted to destroy the Antosians but was prevented from doing so. However, Garth killed both his executive officer and second officer. (TOS novel: Garth of Izar)
In 2268, when USS Enterprise was delivering a new therapy to the colony, Garth masqueraded as Governor Donald Cory and kidnapped both Kirk and Spock. After their release, the therapy was administered to Garth.
- Different sources have Garth in command of different vessels at Axanar. (The name of his ship is unrevealed in "Whom Gods Destroy"):
The Four Years War
In this Star Trek: The Original Series novel, Garth commanded USS Heisenberg at Axanar and Antos IV, in 2251.
Garth was in command of USS Lexington at Axanar.
In the early 2250s, Garth commanded Task Force Constitution from USS Constitution. Ships assigned to the task force included USS Avenger and USS Illustrious. (Star Trek: Avenger: "Early History of USS Avenger")
In the 2250s, Garth wore the assignment patch of the USS Excalibur and was one of the senior officers monitoring Cadet James T. Kirk's attempts at the Kobayashi Maru scenario. (Origins: The Protracted Man)
In this Star Trek: Discovery novel, Paul Stamets recalled that Garth had commanded the Heisenberg in 2251, but rechristened the ship Ares during his attempted genocide of Antos IV that year.