Johnny K

Johnny K was a member of Joker's Gang.

Arkham City Incident
Johnny K and several other inmates were dispatched by the Joker to Arkham City's subway, to hunt the rest of Penguin's thugs. Penguin's henchmen were killed by Joker's thugs. Johnny K and some other henchmen went to Wonder City's destroyed streets and Wonder Tower's foundations. A thug asks the armored thug what happened to Johnny K. The armored thug answers that Johnny K was sliced by Assassins, working for Ra's al Ghul.

Trivia

 * Johnny K is mentioned in a conversation of Joker's thugs in the destroyed streets during the hunt for Ra's al Ghul's blood.