Origin
Senor Alvarez is a international criminal, who has no loyalties to the men he works with.
Creation
Senor Alvarez was created by Dennis O’Neil for his run of The Joker.
Major Story Arc
Double Jeopardy
For more information see: The Joker #1 – The Joker’s Double Jeopardy
Senor Alvarez breaks Two-Face from Arkham Asylum but disrespects the Joker, saying “Two Face is a better criminal mastermind”.
Later Alvarez explains to Two-Face he broke him out to steal 10 gold double headed Spanish doubloons from the Gotham Museum. Before he can lay out his plan, Joker busts into the room and hits Alvarez in the face with an acid pie.
Alvarez was later found and taken to the hospital where it was revealed that he had already stolen the doubloons and had left counterfeits. This was all in a play to double cross Two Face and escape with the real coins. This plan was stopped by the Batman, who learned of Alvarez’s plan, and Joker putting Alvarez in the hospital.