With Teenage Mutant Ninja Turtles: Out of the Shadows set for release just two years after the 2014 Jonathan Liebesman-directed reboot, Dave Green's (Earth to Echo) sequel has all the promise to better the first that made a tidy $493 million at the worldwide box office. As well as the core returning characters comprising of Leonardo, Donatello, Raphael, Michelangelo, April O'Neil (Megan Fox), Vernon (Will Arnett), Splinter (the voice of Tony Shalhoub), and Shredder (Brian Tee); new faces join the expanding roster, including Casey Jones (Stephen Amell), Bebop (Gary Anthony Williams), Rocksteady (Stephen Farrelly), Kraang (Brad Garrett), and Baxter Stockman (Tyler Perry).

Picking up after the climactic battle where the turtles square off against Shredder at the end of the first movie, Green introduces fans to a collection of iconic characters that, for various valid reasons, simply couldn't fit into the previous film. Bebop and Rocksteady, for example, were meant to feature in Teenage Mutant Ninja Turtles but the huge scope and CGI challenge was, as Brad Fuller revealed in an interview with us, already huge enough:

"Those were two characters that we wanted to put into the first movie. In fact, when we pre-vis’ed the first movie, we pre-vis’ed 4 or 5 scenes, there was a sequence of Bebop and Rocksteady in that pre-vis. When it ultimately came time to make the movie, we recognized that the sheer magnitude of trying to create a movie with five CG leads was so much to bear that we just couldn’t put Bebop and Rocksteady in it."

Bebop and Rocksteady TMNT 2 Teenage Mutant Ninja Turtles Out of the Shadows

Clearly though, a mere 24 months later, such restrictions don't apply in the same way now -- the basis for the four turtles (in terms of CGI groundwork at least) was already in place, so the idea of adding more CGI characters wasn't as daunting or likely as time consuming as starting from scratch.

"So if the fans wanted them or didn’t want them, we knew they were going to be in the second film, because we couldn’t get them in the first film. We always said if we were lucky enough to make another one, those characters we want to get in."

It is interesting to hear that Shredder's bumbling goons were meant to appear in the first film because that's what most fans expected. Fans will know that the TMNT cartoon series was nothing without Bebop and Rocksteady at Tin Grin's side, but even though they didn't feature in the 1990 live-action movie, it's satisfying that they're finally involved.

"You're never laughing at Shredder in this movie. He is a hard ass and he’s very serious. Unfortunately, he has chosen these two characters, Bebop and Rocksteady, to support him. And that is ultimately, I imagine, frustrating to him that they are so big and strong but yet so stupid."

Shredder in Teenage Mutant Ninja Turtles (2014)

And it's also reassuring to learn that Shredder won't develop into a daft comedy character fit for ridicule as so easily could've been the case. The idea of him being a dangerous, powerful enemy to the turtles has always generated the tension and ongoing friction -- knowing that, if he could, he'd kill the heroes in a half-shell in a heartbeat. So the idiocy of his henchmen serves as something of a contrast to their boss's serious intention and demeanor.

"I would say that the most requested character in the second movie was Kraang. And so, it’s not like we weren’t going to put Kraang in it, but the fans wanted it and we wanted it, so we did that. Then Baxter Stockman is a character that we all here love. We actually put Baxter Stockman in the first film. I’ve never said exactly where it is, but there is a scene in the first film where Baxter Stockman is standing in the background. So that was always kind of our plan, was to put him in the second film. And that’s how the whole thing came together."

Naturally, every fan was aching to see Kraang materialize on the big screen, considering he had only existed in cartoon form in the late-1980s and throughout the 1990s and before that in comic book form. The big test will be whether the alien warlord is convincing in all his CGI glory, and also if he manages to slot into the TMNT cinema universe with relative ease.

Next: Stephen Amell Explains How Casey Jones Is Different

Teenage Mutant Ninja Turtles: Out of the Shadows hits theaters June 3, 2016.