"When Billy Batson speaks the name of an ancient wizard, he is magically transformed from boy to man -- the world's mightiest mortal!"

That name is Shazam and he becomes Captain Marvel.

The SHAZAM story started in 1939 and apparently as of 1994 was still going... I should note however that I have never seen a SHAZAM comic, I have seen the odd Captain Marvel toy in stores, and I only know the name because my Uncle used to dress up in a cape and try to fly off the coffee table (according to my mother).