Mumbai, Sept 1 : The latest outing of 'Teenage Mutant Ninja Turtles' with the film 'Mutant Mayhem' is a comic one. As so much comedy was involved, this led to a bunch of improvisation, with Post Malone voicing Ray Fillet who ended up singing the character's name throughout the movie as his only line. Director Jeff Rowe, recalling the process, said with a smile: 'We were desperate to have Ray Fillet in this movie because he's one of our favorite characters. But we couldn't figure out what he would do in the film. I had this idea that he'd be like Matt Damon in Team America, where he just had the one line he'd say over and over." He further mentioned: 'At the same time, there were conversations going on that Post Malone might be interested in doing something in our film. So I said, 'Would he be interested in being Ray Fillet, and just singing that name really beautifully ' as his only line ' in the film'? Unbelievably, he said 'Yes'.' Producer James Weaver, detailing the process of creating the jokes, said: 'We were trying to figure out a joke for all the mutants. With (humanoid manta ray) Ray Fillet we said, 'What is the joke'? We wondered, 'What if he just sings his name'? Post was one of the last people to record. We had no idea what that was going to sound like. And then in the first screening you just have Post Malone singing 'Ray Fillet' and it just can't help but make you smile.' Ray Fillet is one of the most popular characters of the TMNT franchise, and is a part of an organisation called, the 'Mighty Mutanimals', a bunch of mutant animals who are comical villains. Ray Fillet was once a human marine biologist who mutated into a manta ray, after being accidentally exposed to a mutagen. Produced by Seth Rogen and directed by Jeff Rowe, the film boasts of a star-studded cast, including Jackie Chan as the voice of Splinter, the vocal talents of John Cena, Post Malone, Seth Rogen, Paul Rudd, Brady Noon, and Maya Rudolph. 'Teenage Mutant Ninja Turtles: Mutant Mayhem' was set to hit the big screen in August, though the date was changed and as such, 'Mutant Mayhem' will hit Indian screens in English and Hindi on September 1, 2023. /IANS