With such a large recurring ensemble, at this point it's a pleasant surprise if Gotham introduces an original character, especially a character from DC Comics that's not already a part of the cast. In the May 1 episode, Bruce Wayne's kidnapping will lead him to a prison, seemingly in the far-off mountains, where his jailer is a Shaman (Raymond J. Barry) who appears to wants to teach rather than torture him. And this surprising development may lead you to wonder if Shaman is from DC comics, or if this mystical and cryptic zen master is an original Gotham creation.
Let's start with this: there isn't a character who exactly matches the description of the Temple Shaman in the comics that inspired Gotham, making him technically an original character. However, with nearly 80 years of history in Batman mythology, there have been so many major and minor characters who've come and gone that yes, there are a few characters who could potentially have been inspirations for the Shaman. First of all, Batman has no superpowers, but he's a highly trained martial artist — in fact, some comics say that he's skilled in literally every martial art on Earth. While that's probably unlikely for any real person, this is Bruce Wayne, the Bat of Gotham.
In Batman: Year One, a famous contained storyline about Batman's origins, Bruce Wayne, as an 18 year-old, returns to Gotham City after spending years traveling and training with different masters around the world. Perhaps meeting the Shaman will kick off Bruce's training journey in Gotham. He's been working out with Alfred, but this could be the beginning of Bruce's real transformation into Batman.
Year One shares a lot of DNA with the later film adaptation Batman Begins, wherein the master who trained Batman was Ra's al Ghul of the League Of Assassins. And while there doesn't appear to be much about the Shaman that resembles the Ra's of that movie, the show does seem to be evoking a similar style in how it's portraying Shaman, right down to the way he uses hallucinations as a tool for enlightenment.
An 1989 to 1990 Batman comic storyline Shaman explains some of the gaps in Bruce Wayne's years abroad, suggesting that while studying with a shaman in a remote part of Alaska, an old folktale gives Bruce the inspiration to use a bat as his alias. Upon his return to Gotham City, Bruce realizes that a score of ritualistic murders committed by the Chubala Cult are tied to the master he once studied under. It's revealed that after another white man, criminal Thomas Woodley, was saved by the same Native Alaskan shaman, he became obsessed with the local deity Chubala, stole local sacred artifacts, and began murdering people in a twisted form of worship.
Whether Gotham's Shaman is inspired by the real shaman or Woodley, that would be an incredibly dark direction in which to take the character. However, using the name Shaman, might be a way for the Gotham writers to at least hint that this training will finally be what inspires Bruce to choose Batman as his mantle.