In style and tone, Billy Batson and the Magic of Shazam! is a followup to Jeff Smith's 2007 miniseries Shazam!: The Monster Society of Evil, as both draw upon the light, whimsical feel of the Captain Marvel comics of the Golden Age for inspiration. In Magic of Shazam!, Billy Batson is a young boy who must juggle his superheroic life as Captain Marvel with looking after his rambunctious little sister Mary Marvel. Unlike Billy, who transforms into an adult when he speaks the magic word "Shazam", Mary possesses only a fraction of his power, although she is faster, and remains a child in her superhero form. Tawky Tawny, a shapeshifting servant of the wizard Shazam, assists them and comes to live with them at their insistence when his form is later fixed as a humanoid tiger. Other Marvel Family characters are similarly re-imagined, such as Black Adam who is presented as bratty exchange student Theo Adam, a classmate of Billy. In their clashes, a boy, Freddy Freeman, is accidentally seriously injured and paralysed and blamed the Marvels for it. Black Adam exploited that hate to recruit him with his power as Black Adam Jr. until the boy realizes the villain's evil and reconciled with the Marvels, which led to Captain Marvel bestowing him a portion of his power to become Captain Marvel Jr.