Captain Marvel (DC Comics) Comics" #21 (1941) introduced the Lieutenant Marvels: three other boys named "Billy Batson" who could also become adult superheroes. Captain Marvel, Jr., the alter-ego of disabled newsboy Freddy Freeman, debuted in "Whiz Comics" #25 (1941). Mary Marvel, alter-ego of Billy's twin sister Mary Batson, first appeared in "Captain Marvel Adventures" #18 (1942). In contrast to Captain Marvel and the Lieutenants, both Mary Marvel and Captain Marvel, Jr. remained kids in superhero form, and were given their own eponymous books in addition to appearing as the lead features in "Master Comics" and "Wow Comics", respectively. Captain Marvel, Captain Marvel Jr., and
Captain Marvel (DC Comics) adversaries in Modern Age comic book stories. The two are often portrayed as equally matched and, while Marvel does not possess Superman's heat vision, X-ray vision or superhuman breath powers, the magic-based nature of his own powers are a weakness for Superman. The National Comics/Fawcett Comics rivalry was parodied in "Superduperman", a satirical comic book story by Harvey Kurtzman and Wally Wood in the fourth issue of "Mad" (April/May 1953). Superduperman, endowed with muscles on muscles, does battle with Captain Marbles, a Captain Marvel caricature. Marbles' magic word is "SHAZOOM", which stands for Strength, Health, Aptitude, Zeal, Ox (power of),