Okay bear with me here as it's my first article and quite a long shot, but here's my idea...
If you're not familiar with the series Red Hood and The Outlaws, the idea is simple, Red Hood (Jason Todd), a rebooted Starfire and Arsenal (Roy Harper) go around the universe getting into trouble as a "non-team."
With Roy already established as Arsenal in Arrow, we already have one character being prepared for this as in the comics he has been abandoned and sponsored by Killer Croc.
However Red Hood and Koriand'r (Starfire) are not in the television shows yet, so here's my theory as how this goes:
What if the Supergirl series is connected to Teen Titans?
With the new series coming up soon it's been speculated that space and aliens will be introduced to the CW-verse, as with meta-humans in The Flash.
Then we have Red Hood, a fan favorite because he is the Robin that died and came back crazy, like seriously crazy. Kill-criminals-as-a-weird-version-of-Batman crazy.
I think that he could appear in the upcoming Teen Titans series, as Nightwing has been confirmed. Also, lets not forget this little bit from our childhood:
I really think that this could happen and to be honest... I would welcome this series any day.