Original: The series also introduced Agustin Guerrero, the original El Gato Negro of the early '50s and late '60s, as a major supporting character.
Simplified: The first El Gato Negro was Agustin Guerrero, a former luchador from South Texas who decided to use his skills to fight crime during the early '50s and late '60s. The current El Gato Negro is Francisco Guerrero, grandson to the original El Gato Negro.