The comic history of the Shazam family - Talking tigers, trademark disputes, and more

gamesradar.com:

Billy Batson's adopted family is central to the Shazam! film franchise, with Billy sharing the powers of Shazam among his foster siblings - a concept that has its roots in comic books. 

And with the villain of Shazam!: Fury of the Gods, Hera, out to reclaim the powers of Shazam, the relationship between Billy Batson and the Shazam Family is at the core of the new film.

But what's the Shazam Family like in comics? Well… sorta different, and often kinda weird. For one thing, they used to be called the Marvel Family, though modern incarnations have adopted the Shazam Family name.

Almost as long as Billy Batson has been saying "Shazam!" and turning into a superhero, he's shared his magical powers with a whole Shazam Family of superheroes, including sisters, best friends, uncles, and even a talking tiger.

Billy Batson, whose classic superhero name Captain Marvel is now best associated with Marvel Comics' Carol Danvers thanks to the magic of trademark, first debuted in 1940 - and by 1942, he was sharing his powers with a long lost sister named Mary Marvel.

Like Captain Marvel to Billy Batson, Mary Marvel is the classic adult superhero alter ego of Mary Bromfield, who was born Mary Batson. When Billy Batson's parents died, Billy Batson lived on his own while Mary was adopted by a well-to-do family named the Bromfields.

When Billy was reunited with his younger sister, he immediately began sharing his power with her with the blessing of The Wizard, who bestowed Billy's powers to begin with. That origin is just a bit different from the Mary Bromfield of the Shazam! movies, but we'll get to that.

Interestingly enough, even though Captain Marvel himself would eventually be deemed a too-close copy of his predecessor Superman thanks