Captain Marvel (DC Comics) abilities. Based on book sales, the character was the most popular superhero of the 1940s, outselling even Superman. Fawcett expanded the franchise to include other "Marvels", primarily Marvel Family associates Mary Marvel and Captain Marvel Jr., who can harness Billy's powers as well. Captain Marvel was also the first comic book superhero to be adapted into film, in a 1941 Republic Pictures serial titled "Adventures of Captain Marvel". Fawcett ceased publishing Captain Marvel-related comics in 1953, partly because of a copyright infringement suit from DC Comics, alleging that Captain Marvel was a copy of Superman. In 1972, DC licensed the
Captain Marvel (DC Comics) its comic book staff. Otto Binder and Kurt Shaffenberger ended up at DC, becoming prominent members of the creative team for the Superman-related comics from 1954 through the 1960s. Shaffenbeger snuck an unauthorized cameo by Captain Marvel into a story in "Superman's Girl Friend, Lois Lane" #42 in 1963. "Whiz Comics" had ended with issue #155 in June 1953, "Captain Marvel Adventures" was canceled with #150 in November 1953, and "The Marvel Family" ended its run with #89 in January 1954. Hoppy the Marvel Bunny was sold to Charlton Comics, where a few Fawcett-era stories from that strip were reprinted