1) Green Lantern
Perhaps because the minds behind the Arrowverse – Greg Berlanti and Marc Guggenheim – previously wrote the 2011 Green Lantern movie, the DC hero they most like to tease is Hal Jordan.
Firstly, Coast City has been namechecked many times across Arrow and The Flash – as is Ferris Air, who Jordan worked for. In The Flash episode “Rogue Air,” Barry mentions how Ferris Air has closed down due to a test pilot going missing, something that happens to be Hal’s origin story.
[zergpaid]If this wasn’t enough, a flashback in Arrow’s fourth season premiere sees Oliver in a bar. The scene opens on a shot of an unseen man in a green military jacket – his name tag reads Jordan.
Sadly, though, that’s as close as we’re probably ever going to get to a Green Lantern/Green Arrow team-up on the show!