Kamala is dressed up as Carol Danvers, so Bruno dressing up as another hero alongside her makes a lot of sense. In the comics, Bruno is actually an aspiring scientist, specifically in the chemical engineering field, so it wouldn’t be a stretch for him to see Bruce Banner as his personal hero, being a famous scientist who doubles as a superhero. Additionally, at least at Peter Parker’s school in Spider-Man: Homecoming, Bruce Banner is comparable to Marie Curie and Sir Isaac Newton.
As pointed out by multiple users on Twitter yesterday, it seems like Bruno dressed up as Bruce Banner, alongside Kamala’s own Captain Marvel costume.
is he supposed to be bruce banner pic.twitter.com/z0SdHvYDs4
— bails ʬ⁸⁴ (@starkindxstries) November 19, 2020
It seems very apparent at this point that Kamala and Bruno are going out for Halloween, both seemingly dressed as their favorite heroes. Kamala was wearing what appeared to be a home-made costume of Captain Marvel’s outfit seen in Avengers: Endgame, and Bruno seems to be emulating Bruce Banner, which is more apparent when comparing his appearance in Avengers: Age of Ultron.