A member of the
Legion of Substitute Heroes Auxilliary.
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.