Since this is an alternate universe, it could be pretty much anything. An entirely new character or even a female version of Barry Allen or Wally West, or any of the others. Not to get too much off-topic here, but on a recent episode of Ultimate Spider-Man, he travels to a parallel universe where he meets Spdier-Girl, a reversed-gender version of Peter Parker named Petra Parker. So they didn't use any of the characters who had the Spdier-Girl identity from the comics (at least as far as I know, and after checking Wikipedia ). They just might do the same for Flash on Gods and Monsters. Of course, we'll just have to wait and see but speculating is fun. As for Green Lantern, I think it would be funny if they used an updated Alan Scott, since he's had the least animated appearances so far.