Grizzlyjin
Supersonic, idiotic, disconnecting, not respecting, who would really ever wanna go and top that
It's weird, because when he was first introduced, he was amnesiac. Superman gave him a name thinking he was Kryptonian, hence Mon-El.
His real in-comic name is Lar Gand. But they're either ignoring that completely on Supergirl, or he's evil. I doubt they'd make him evil though. He's a solid backdoor into Legion of Super-Heroes if Legends of Tomorrow dies.
Yeah, I thought it was weird how he just came out with "My name is Mon-el." They could have had him escaping because he had amnesia and was confused. I wonder if he's lying and will be partially responsible for whatever happens to start the big crossover.