The DC Comics universe has never been bigger on the small screen, with Arrow and The Flash currently airing on The CW, Gotham on Fox, Constantine wrapping up its first season on NBC and CBS developing Supergirl. We reported last month that a crossover between Arrow, The Flash and Supergirl is likely, since Greg Berlanti serves as executive producer on all three shows, even though Supergirl airs on a completely different network, but no exact details for this crossover have been revealed. During an appearance at Dallas Comic Con Fan Days, Arrow star Stephen Amell addressed the possibility of crossing over with Supergirl and Constantine, but adds that it would be "tough" to pull off a Gotham crossover.

"It would be interesting. I was saying this earlier. It would be interesting to cross over with Constantine, only because he knows a lot about the Lazarus Pit, which is something that we've introduced in the show this year. It would be cool to crossover with Supergirl because it's something with Greg Berlanti, who's the helmer and sort of the brain trust or the center of the brain trust of Arrow and The Flash and I know so many of the people that are involved in the production of that show so that would be really interesting. And Gotham would be a tough one, just because I think they're out in a different time but the crossover with The Flash was so much fun and did so well that I can't imagine a world -- a universe, no pun intended -- where that didn't happen and continue to happen all the time."

Of course, no plans are in place yet for a crossover with Constantine or Gotham, especially since Constantine is facing an uncertain future. We reported yesterday that the show may be re-branded as Hellblazer and move to the Syfy network for Season 2, but those plans are not set in stone yet. It should be noted that neither Gotham or Constantine have any connection to The CW shows except that they come from the DC Comics universe, and they don't share the same executive producers like Arrow, The Flash and Supergirl. It's also worth noting that CBS does own half of The CW Network, which would make a crossover between Arrow, The Flash and Supergirl even more plausible. Though, CBS network chairman Nina Tassler shot down reports of a crossover last month. If Supergirl does well, that could all change. What do you think about Stephen Amell's comments? Are you looking forward to Arrow crossing over with Supergirl?