Amell says that the film is in many ways Casey's origin story, a police officer whose clean-cut life changes when he meets the sewer-dwelling heroes. Amell had never read the comic books. "I'm a fan principally from the movies, actually," he says "The three movies that came out timed up nicely with me in elementary schools. And I actually remember going to three successive birthday parties where we would go see the Turtles movie and then we would just go home and eat cheese pizza until everyone was sick to their stomach! So when I booked the job, my wife, who was also a huge fan and had a turtles-themed birthday party, actually remembered Casey Jones much more than I did. I think she was more excited about this role than I was!"

The Turtles in Teenage Mutant Ninja Turtles 2

But Amell threw himself into the role. "I just wanted to have fun. I wanted to bring an edge of humour, and not take myself too seriously," he says, laughing off comparisons with his action training for Arrow. "I wouldn't say this is a new skill set, but I would say that Casey's certainly a different type of fighter than I am on television. He has different skills. I wanted to make sure that, especially the first time we see Casey Jones, that he wasn't necessarily a super-polished fighter. He's more flying by the seat of his pants, which is a departure from what I'm used to."

But was it daunting to step into another role with a very vocal fanbase? "Nope, not at all," Amell says. "If I were to choose between a project that has an incredibly passionate fanbase and a project where they are discovering something for the first time, I'd pick the project with the incredibly passionate fanbase. I'll join as many franchises with passionate fanbases as humanly possible! I like going into roles where people have an expectation. I actually kind of like going into roles where other actors in recent memory have played the character. Because in those instances, both with Oliver Queen and with Casey Jones, we are meeting the character at a very early part of his evolution. So the traditional Casey Jones people have come to know and love will emerge over the course of time."

Watch the trailer for TMNT 2: