One recurring joke in Shazam! subtly makes a Marvel character canon within the DCEU, and it creates a small but glaring issue with the franchise's continuity. The DCEU may have begun on shaky ground with a number of divisive films, but 2019's Shazam! was widely praised for the much-needed levity it brought to the DCEU. By telling the story of Billy Batson, a boy granted the ability to transform into the powerful hero Shazam, the film was able to inject humor and a slightly more light-hearted tone into the franchise, which was especially important after criticisms that the DCEU was too dark and gritty.
Shazam! serves as an origin story for the titular hero in the DCEU, and as a result, much of the film focuses on Batson learning to manage his new dual identity. After discovering his powers, he begins searching for a superhero name, and it's a running joke in the movie that Billy finds it difficult to decide on a definitive moniker for his alter-ego. One of the many names given to Shazam when he starts trending online is "Zap-tain America", a name that's repeated once or twice throughout the movie. It's an obvious nod to Marvel's Captain America, taking Shazam's lightning powers into account in service of the pun.
Related: Shazam 2's Helen Mirren Role Creates A Weird DCEU Paradox
The use of the pun seemingly makes Captain America canon within the DCEU, despite the fact that he's never been mentioned before. Though he may simply exist as a fictional character in the franchise, the idea that the DCEU features both very real, tangible heroes and then separate, fictional ones is a little jarring. It also begs the question of which other Marvel characters exist within the DCEU, and why it hasn't come up more frequently
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