Who's Old Now?
is a Danny Phantom and Shazam! crossover story. Danny has retired from the hero game, but comes to the attention of the Justice League when Captain Marvel calls him about a ghost causing issues. Due to what they heard of the conversation, the League assumes that Captain Marvel is Danny's adoptive father, when in reality the opposite is true due to how becoming Captain Marvel makes Billy Batson look older, while for Danny his human form has aged but his Phantom form hasn't. They run with it.
- Clones Are People, Too: Discussed by Elle and Kon in Chapter 7.
- Entertainingly Wrong: When Captain Marvel calls Danny for help with a ghost, the League assumes that the Captain adopted Danny due to the looks of their alternate states, when it's really the other way around.
- Happily Adopted: Danny has taken in Billy as his ward, even homeschooling him so he has time to do his heroic duties without it interfering with his schoolwork like what happened with him.
- I'm Having Soul Pains: On the week around the anniversary of a ghost's death, they're effectively bedridden with the pain of said death, combined with their obsession going into overtime.
- Older Than They Look: Danny's ghost form still looks as if he's fourteen, despite his human side having aged normally.
- Retired Badass: Danny, while still pretty powerful, has retired from being an active hero by the time of the story.
- Secret Secret-Keeper: Martian Manhunter's telepathy combined with the fact that mental shielding is a rarity on Earth means that J’onn is often aware of secrets his fellow League members have, including the truth about Captain Marvel's and Danny's ages, but he doesn't say anything so as to respect their privacy.
- Secret-Keeper: Jason Todd/Red Hood is one of the only non-family members to know the truth about Captain Marvel and Phantom.
- Sure, Let's Go with That: The League assumes that Captain Marvel adopted Phantom when it's really the other way around, and the two simply let them think that.
- Younger Than They Look: As in canon, Billy's Captain Marvel form makes him look a lot older than he actually is.
