It seems inevitable that at some point John Constantine will show up on the upcoming Swamp Thing TV series, and Matt Ryan wants in.
Despite having a Constantine series canceled by NBC, it seems Matt Ryan has found his place in the world playing the paranormal investigator John Constantine. As we said he played him on NBC, but when that ended Arrow brought him on, he did some animation work, and eventually landed on Legends of Tomorrow.
Appearing at Wizard World Cleveland recently, Ryan said, “John Constantine was born in Swamp Thing. Eventually, he has to be on Swamp Thing, and I just hope it’s me… I’m still playing this role four years after Constantine was actually canceled, so I must be doing something right.”
The main issue with this idea is that it appears that the DC Universe series are in multiple continuities, none of which touch The CW Arrowverse. How his presence would be explained would be tricky, but as all of this deals with magic and the paranormal, certainly an excuse could be found. It can even just be suggested that Constantine exists everywhere. Or it even could just be ignored and happen.
Swamp Thing is currently filming and has been for some time now, so season 1 seems unlikely, but we could always hope for season 2.