Captain S'slee (also known as S'alath or S'salk) was an officer of the Gorn Hegemony's military in 2267. He commanded the MA-12-class cruiser Gress'sril that destroyed the Federation outpost on Cestus III. S'slee was forced by the Metrons to battle Starfleet Captain James T. Kirk in order to settle their differences. Kirk astounded all by besting S'slee and then letting him live, refusing to allow the Metrons to goad him into committing what he saw as murder. This impressed both the Metrons and the Gorn, and S'slee would often recount the honor of the combat and take pride in the scars from Kirk's cannon-blast. S'slee grew old and eventually began to suffer the effects of old age on his mind. He devised an elaborate death for himself, living out the end of his days on a remote, deserted planet fighting holograms depicting Kirk. (TOS episode & Star Trek 2 novelization: Arena; FASA RPG modules: Star Trek IV Sourcebook Update, Demand of Honor; TOS - Unlimited comics: "Dying of the Light", "The Veteran", TOS video game: 25th Anniversary)
This character was referred to as S'slee in the FASA Corporation's RPG modules, and was given the alternate name S'alath in Marvel Comics from the Star Trek Unlimited series. The CCG set These Are the Voyages called this character S'salk. It's possible that the various names all form part of some long-form name or surname.
The character of Commander Raaskaa was intended to represent this character, but the licensing office at Paramount Pictures requested that the reference be removed from TOS - The Return of the Worthy comic: "Great Expectations!". The character was recolored as a scarlet lizard, and spiky black hair was drawn onto it. The editors intended for this to change the species, and several pieces of dialogue were altered to call the scarlet Gorn a "Lath". However, the word "Gorn" was included in the issue several times as the editors had missed several mentions that were supposed to be altered.