The main bad guy's name is Mauvais. In French language, Mauvais means Bad.
In The Night of the Glowing Corpse (1965), Jim West also fought against an evil character who lost his leg in a train accident.
Theodore Marcuse (Gustave Mauvais) would later guest star in the similarly themed Devil's Island (1966).
Mauvais' henchman is named "Le Cochon." Translated from the French, it means "The Pig."
West's and Reed's deranged cellmate (noted character actor Steve Franken) is called "Le Fou," which translates to "The Fool."
The setting for this episode, Devil's Island, was a famous prison of the 19th and 20th century. It operated at several locations in French Guiana (South American continent), and was perhaps best known as the prison for French Army Capt. Alfred Dreyfus, who was wrongfully convicted of treason.