Fawcett Comics, a division of Fawcett Publications, was one of several successful comic book publishers during the Golden Age of Comic Books in the 1940s. Its most popular character was Captain Marvel, the alter ego of radio reporter Billy Batson, who transformed into the hero whenever he said the magic word "Shazam!". Other characters published by Fawcett include Captain Video, Hopalong Cassidy, Ibis the Invincible, Bulletman and Bulletgirl, Spy Smasher, Captain Midnight, Phantom Eagle, Mister Scarlet and Pinky, Minute-Man, Commando Yank and Golden Arrow. Aside from the better known superhero books, Fawcett also published a short-lived line of horror comics during the early 1950s, a string of titles which included This Magazine Is Haunted, Beware! Terror Tales, Worlds of Fear, Strange Suspense Stories, and Unknown World. Other genres included teenage humor (Otis and Babs), funny animal (Hoppy the Marvel Bunny), romance (Sweethearts), war (Soldier Comics) and Western (Lash LaRue, Six Gun Heroes). Fawcett also produced comics based on contemporary movie stars (Tom Mix, Monte Hale) and matinee serials (Nyoka the Jungle Girl). The entire line was dropped in 1953, when Fawcett closed down their comics publishing wing (though many titles were picked up by Charlton Comics. Fawcett Publications began in 1919 with the magazine Captain Billy's Whiz Bang and eventually expanded into a line of periodicals with a combined circulation of ten million a month. The company joined in the explosion of comic book publications in the United States in the late 1930s and early 1940s. Its initial entry, developed by writer Bill Parker and artist C. C. Beck, was Thrill Comics, a single issue of which was published only as an ashcan copy. The content was then reworked (for example, the lead character of Captain Thunder was renamed to Captain Marvel) and published as Whiz Comics #2 (Feb. 1940).