Another Arrow and The Flash crossover is in the works. This time Arrow's John Diggle and his wife Lyla Michaels from Starling City will travel to Flash's Central City to assist Barry Allen in taking down King Shark.
Arrow actor David Ramsey previously hinted at the same through an Instagram post. He posted a picture of himself outside The Flash writers' room and wrote, "Made a visit to The Flash writers room. Can only mean one thing.. Arrow& The Flash"
Comic Book has confirmed the news and added that the crossover will take place in the 15th episode of The Flash's second season. Showrunner Andrew Kreisberg told Comic Book, "The Diggles arrive in Central City to help Barry take on King Shark who has escaped from ARGUS and is hellbent on completing his mission of destroying The Flash."
King Shark is a humanoid shark-man, and he made a brief appearance on The Flash in season 2's episode 4, where he nearly kills Barry before Harrison Wells from Earth 2 showed up with a gun to save the speedster.
"It was just fun for us, because obviously we can't afford to do an entire King Shark episode, so the idea that he's one of Zoom's minions," Andrew Kreisberg had said back in October 2015. "He said, 'Zoom sent me here to kill you.' He's just the latest in another line, which does mean that there is a King Shark on Earth-1, now that we've designed him."
Arrow season 4 and The Flash season 2 are currently on hiatus and will return with new episodes on 19 January and 20 January respectively on The CW Network.