Dyvud/Frenk Retzun of the planet Janus is the real name of Double-Header. The natives of Janus replicate by asexual reproduction, splitting into two twins with the same chromosomes. In the case of Dyvud and Frenk, the two halves do not get along and are constantly fighting. Due to their bickering, the Legion of Super-Heroes rejected Double-Header for membership.

Double-Header applied for membership in the Legion of Substitute Heroes, but was found to not have powers worthy of membership and was relegated to the Subs Auxilliary.