Before he became Superhero Freddy Freeman in the Shazam! movies, Adam Brody had a small role in the DC series Smallville. Based on the DC comics, Smallville ran from 2001-2011 and followed the younger years of Clark Kent's life as he came to terms with his powers and newfound responsibilities as the infamous hero, Superman. While the series did include several of Superman's greatest villains, such as Brainiac, Darkseid, and Lex Luthor, some of Clark's biggest trials could be found at the beginning of the series, where he was forced to take on several powerful metahumans and meteor infected individuals while trying to navigate his way through high school.
These were known as the "Freak of the Week," which was a structure that mainly took place in season 1 and 2. Most of the stories revolved around a character who had been infected by green Kryptonite and soon spiraled down a dark path as they struggled to deal with their powers and the effects that came with it. However, there were a few minor antagonists who seemed to have been born with the abilities. Interestingly, these characters were played by highly acclaimed actors, including Adam Brody, who went on to play Superhero Freddy Freeman in the Shazam! movies (and almost Barry Allen/The Flash in George Miller's canceled Justice League: Mortal movie).
Adam Brody Played Metahuman Student Justin Gaines In Season 1 Of Smallville
Debuting in the season 1, episode 19, "Crush," Adam Brody made his first and only appearance as Justin Gaines. Justin was a talented and artistic student who attended Smallville High School with Clark, Chloe, Lana, and Pete. After being involved in a hit-and-run accident, Justin had woken up and discovered that he had sustained life changing injuries to his hands and he wasn't able to hold a pencil as well anymore. However, he seemed to still be able to draw as the accident awoke latent telekinetic abilities.
Still, this didn't satisfy Justin and he decided to get revenge on all those who had wrong him, injuring the unprofessional surgeon who damaged the nerves in his hands further and killing Principal Kwan after believing he was the driver who left him for dead (when it was his son who was responsible). Although Clark was already suspicious of Justin due to his developing relationship with Chloe, it didn't take long for him to work out what he had done. Eventually, Justin's was caught and sent to a psychiatric facility.
It's easy to see why Justin is considered to be one of the more sinister villains Clark had faced as he didn't seem to express any remorse for his actions and was just full of hatred. Brody's stint was also quite fascinating since this was the first time viewers had met a metahuman who hadn't been infected by green Kryptonite, which seemed to suggest that the writers were going to begin moving away from the "Freak of the Week" structure.
Adam Brody's Justin Gaines & Super Freddy Freeman Are Completely Different
18 years after debuting as Justin Gaines in Smallville, Adam Brody appeared in another DC project: Shazam!. Unlike his role in Smallville, Brody was cast in a main role and played the older version of Freddy Freeman (known as Captain Everypower). While Justin decided to use his powers for evil, Freddy went down the more altruistic path and decided to use his abilities to help save innocents. If anything, Freddy has a lot more in common Clark: he had superhuman strength, endurance, could fly, and cared deeply for his friends and family. If Justin had these abilities and traits on Smallville, there's no doubt that the two would have gotten on a lot better.
Adam Brody Almost Played Barry Allen/The Flash In Justice League: Mortal
Although Brody only had a small role on Smallville, the superhero genre did seem to have evoked an interest in the actor as he did almost star as Barry Allen/The Flash in George's Miller's Justice League: Mortal, which was canceled in 2008. It's unfortunate that this couldn't have been since it would have allowed Brody to show how much he had learned from his experience on Smallville. While Justin isn't as honorable or kind as Barry, Brody did portray the socially awkward and geeky character who is struggling to fit in world perfectly. It would have certainly been interesting to see if Brody used the same mannerisms and techniques here too.