Vargas is one of around forty SPECTRE operatives under the command of Emilio Largo. He only briefly appears in Thunderball.
The character is notable for being the man who coldly kills Giuseppe Petacchi, the Italian pilot who is bribed to hijack the Vindicator bomber and its atomic payload.
- "[The mechanic] reached into his overalls and took out a packet of Camels. He offered one to the killer [Vargas], who took it, broke it carefully in half, put one half behind his ear and lit the other half. The killer was a man who rigidly controlled his weaknesses."
- ― Thunderball - Chapter 9, Multiple Requiem
A short, thick man with a very direct gaze, his distinguishing feature is a stoical professionalism and rigid self-control. In the novel, these characteristics are shown to not be unique to Vargas and apply to the entire Disco Volante crew.