 Although Captain Marvel had been given part-time sidekicks in the form of the look-alike Lieutenant Marvels in "Whiz Comics" #21 (Sept. 1941), Fawcett Comics editor Ed Herron wanted to introduce a distinctive spin-off character.Captain Marvel transformed from teenage boy to adult superhero with a magic word; Herron decided his new character would remain a teenager to differentiate him from Captain Marvel.Fawcett staff artist Mac Raboy designed the new character, named Captain Marvel Jr., using a more realistic style parting with C.C.