I have a semi-realistic way for Bat-Mite to appear in The Batman universe rooted in people’s first hand accounts about meeting “imps” or “elves” on the hallucinogen DMT.
Perhaps Mad Hatter, Scarecrow, or Joker drugs Batman with some kind of DMT derivative and Batman meets “Bat-Mite”, a reality-warping fifth dimensional imp that resembles the “machine elf” entities described by Terrence McKenna in his experiments. Batman could have an intense traumatic trip, but he emerges with knowledge on how to improve himself and defeat his enemies. It could be a powerful climax to a Batman film that hasn’t been witnessed before; emerging from an awful psychedelic trip with a new understanding of life’s purpose. It would be more of a mental battle than a physical one, but still grounded in reality. A number of Batman villains regularly dose Batman with psychedelic drugs, it wouldn’t be unreasonable for something like this to occur onscreen.
View attachment 52512
Source for the image on the right is the Wikipedia DMT entry, it’s an artist’s depiction of the “imps” or “elves” people describe meeting. Bat-Mite could look like this, but more Bat-themed. It could be an opportunity for some truly insane psychedelic visual sequences.
The whole Riddler/Zodiac, Batman/Cobain real life inspirations have certainly gotten the wheels turning in my head. Even with a completely unrealistic character like Bat-Mite, it can be a fun thought experiment to pick out possible real-life claims (be they true or false) for inspiration. The closest thing I can think of is these imps people describe meeting on DMT.