Development Following the release of
Teenage Mutant Ninja Turtles (2014) and its sequel,
Out of the Shadows (2016),
Brian Robbins felt that the
Teenage Mutant Ninja Turtles film series was in dire need of a
reboot. He sought advice from longtime
Turtles toy manufacturer
Playmates Toys, who told him that the reboot should be an animated film. In 2018, Robbins discussed with newly appointed executive vice president of
Nickelodeon Animation Studio,
Ramsay Naito, who to bring onto the project.
Seth Rogen was decided upon, and
Jeff Rowe joined the project soon after. In June 2020,
Deadline Hollywood reported that Nickelodeon Animation was developing a
CG-animated Turtles film for
Paramount Pictures. Rowe was hired to direct, from a screenplay by
Brendan O'Brien. Rogen,
Evan Goldberg, and James Weaver produced through their production company,
Point Grey Pictures, which is credited alongside
Nickelodeon Movies. Naito and Josh Fagen oversaw production for Nickelodeon and Point Grey, respectively. In an August 2020 interview with
Collider, Rogen said that the film would heavily lean into the teenage element of
Turtles. He stated, In June 2021, Rogen revealed a teaser image through his
Twitter page, which contained school notes written by
Leonardo, the film's original release date, and other details. By October 2021, the film was under the working title
Teenage Mutant Ninja Turtles: The Next Chapter. Production designer, Yashar Kassai, elaborated on the project, "You anchor yourself enough in the familiar elements of it so that it is easily recognizable, but then you either add to or enhance some of the existing charm of the franchise." The title
Teenage Mutant Ninja Turtles: Mutant Mayhem had been finalized by August 2022. Kyler Spears joined the film as co-director, signing on because he had worked with Rowe on his prior film,
The Mitchells vs. the Machines (2021). J.J. Villard was commissioned to design the film's logo. Overall, the budget was $70million at minimum.
Writing Rogen, Goldberg, and Rowe, along with the writing team of
Dan Hernandez and
Benji Samit, received screenplay credit, with O'Brien and the former three having "story by"
billing. Rogen and Rowe wanted the film to emphasize the teenage aspect of the Turtles. Rowe compared
Mutant Mayhem to the
coming-of-age films,
Stand by Me (1986) and
Lady Bird (2017) and remarked that his goal was to make "the ultimate teenage coming-of-age film". He described the Turtles as having an "inauthentic confidence that teenagers have", adding that teenagers often ''operate with this hyped-up sense of, 'We can do anything! The writers wanted to create their own version of
Turtles lore and did not take all elements from previous iterations into account. Rowe explained that they aimed "to make it more logical", and skated past a lot of things "to make it really operate from a place of character and relatability". Rowe cited his admiration for the classic
Turtles toys as the reason why a lot of mutant characters were written into the film.
Shredder was originally the main villain of the film, but was written out because Rowe wanted the film's villain to be a mutant who could relate to the Turtles and who the Turtles could relate to and be tempted by. Superfly was originally going to be a mutated version of
Baxter Stockman, a character who has been turned into a mutant fly in past
Turtles media. The two ultimately wound up being separate characters. An early draft of
Mutant Mayhem was more of a high school film. Rowe explained that with the initial version, it was hard to make the Turtles' lives intersect with the crime villain plot in a natural way, adding that the Turtles had already achieved their goal early on in the script. As a result, the film had to "reset 30 minutes in", and new characters, other kids in the high school, and relationships had to be established. Rowe described it as "tedious". Eventually, in July 2022, Rogen approached Rowe through text message, telling him that the film was "fundamentally broken" and had to be completely changed, a sentiment with which Rowe agreed. Consequentially, in the next four months, the film was completely rewritten and boarded into its final state.
Casting and voice recording On March 4, 2023, during the
Nickelodeon Kids' Choice Awards, Rogen revealed that actors
Micah Abbey,
Shamon Brown Jr.,
Nicolas Cantu, and
Brady Noon (all of whom were in attendance) had been cast in the voice roles of the Turtles:
Donatello,
Michelangelo,
Leonardo, and
Raphael. Other cast members revealed in their respective roles in the ceremony were Rogen himself,
Hannibal Buress,
Rose Byrne,
John Cena,
Jackie Chan,
Ice Cube,
Natasia Demetriou,
Ayo Edebiri,
Giancarlo Esposito,
Post Malone,
Paul Rudd, and
Maya Rudolph.
Mutant Mayhem marks the first time all four Turtles are portrayed by teenage actors. Rogen felt that the decision to cast teenagers for the parts in the film, made it stand out from previous versions of
Turtles, saying "something very intuitive became something that really opened up our version". Hundreds of actors auditioned for the roles of the Turtles. Rowe watched every tape and narrowed them down to the ones he felt worked. He edited voices into the character designs to see which suited which. After narrowing it down to ten, Abbey, Brown, Cantu, and Noon had a chemistry table read together, with them ultimately landing the roles. Rowe described the four as "perfect", and the table read as "kinetic and alive". In recruiting Chan, he wrote a letter to him asking if he wanted to be part of a
Turtles film. The team held a meeting with Ice Cube, who, when told his character's name was Superfly, laughed and agreed to sign on. Ice Cube also chose to sign on because of his and his son's emotional connection with the
Turtles franchise. Abbey drew from the characteristics of his friends and previous portrayals of the character for his performance as Donatello. Brown did not want to do the typical "surfer dude" voice for Michelangelo during the audition process. Inspired by
Brandon Mychal Smith's take on the character in
Rise of the Teenage Mutant Ninja Turtles (2018–2020), he sought to do his "own thing with it". Cantu wanted to bring a "quality of nervousness" to Leonardo, feeling that there was a "level of anxiety that comes with leading the group". Noon wanted to balance Raphael's rage with a more lighthearted and funny performance to make him more relatable. In portraying
April O'Neil, Edebiri wanted to hearken back to her teenage years and tap into her character's determination.
Turtles co-creator
Kevin Eastman appears in a voice cameo as a citizen that helps Splinter during the climax, credited as "Good Human". Rowe wanted the role to be voiced by "someone meaningful to the franchise", and chose to cast Eastman as an homage to
Stan Lee's cameos in
Marvel Comics adaptations until his passing in 2018.
Scumbug uses a blend of different voices, including Rowe's, but is ultimately credited to
Alex Hirsch. In contrast to the norm for animation, the cast recorded their voice roles together in groups rather than independently from one another. A single recording session could include up to seven actors. This environment allowed for the cast to play off each other as well as employ a lot of improvisation in their performances. Rogen was partly influenced to apply this approach to the film from his experience recording
The Lion King (2019) with
Donald Glover and
Billy Eichner. He directed particular praise towards Abbey, Brown, Cantu, and Noon and said that they tried to "capture the way they actually interacted with each other" in the film. He recalled an account of one recording session with the quartet and how "they would all hang out together in the kitchen of the recording studio, and they would all just talk over each other and make fun of each other; screaming at each other." According to him, the event was what pushed them to start having the four record together, as he felt that the energy was right for the film.
Design Like with his previous outing,
The Mitchells vs. the Machines, Rowe wanted
Mutant Mayhem to look different from what was expected from an animated film. The director's aim was to make it heavily resemble the concept art. He was inspired by sketches he made in school notebooks as a teenager and how they tend to have a lot of exaggerated features, spikes, and random effects lines, and wanted the film's animation to reflect a similar feeling. Rowe described the film's sketch look as its "North Star", as the comic book-inspired look was for
Spider-Man: Into the Spider-Verse (2018). Production designer Yashar Kassai found working out the style of the film one of the most difficult parts of the production. He and Rowe encouraged the artists to embrace their imperfections and draw like teenagers. Kassai cited the
1987 television series and the
classic toyline as big inspirations for the production team. "We were looking back to the time when sophomoric gross-out humor was the comedic style of the day. So we started there, but then we added the teenage drawing aspect on top of it as a very strong top layer." The visuals were also heavily influenced by
Wong Kar-wai's films, such as
Chungking Express (1994), and the street photography of
Alex Webb. The team would select two to three colors for a scene and aim to adhere to realistic photographic principles, contrasting with the abstract design philosophy. Since a lot of the film takes place at night, the artists spent a lot of time diversifying what New York looks like at night and giving it a variety of different color schemes. Rowe and lead character designer Woodrow White pushed for less bulky versions of the Turtles and to have the main four sport more teenage builds. Similar to Michelangelo and his braces, Donatello was given glasses not as a defining trait of geekiness and wisdom but rather as one of adolescence. With Splinter, White wanted to lean into the dad aspect of the character and have him look disheveled "from the stresses of parenthood." As a ninja master, Splinter wears a
kataginu he cut from a bathrobe, which also reflects the
DIY nature of the character. Additionally, White gave him sweatpants, which he described as "a common staple of stay-at-home parents".
Jeff Bridges's Dude character from
The Big Lebowski (1998) served as inspiration for Splinter's fashion, while his build was inspired by
Danny DeVito. White also studied photos of actual rats when designing the character. For Splinter's fighting style, the filmmakers studied his actor, Jackie Chan, in films such as
Police Story (1985) and
Rumble in the Bronx (1995). White did not want to make
Leatherhead look too muscular, but rather very much like what an actual alligator would look like if it stood on two legs. He collaborated with Kassai when designing
Genghis Frog and based the character's look on that of a
pixie frog. Rocksteady was given a larger head to emphasize the character's horn, which White felt was a rhinoceros's defining feature. With
Ray Fillet, he wanted to give the character a more "menacing edge" and "inject more manta ray" into him. Similarly, White wanted
Wingnut to be more bat-like than previous versions of the character by keeping her wings on her arms.
Animation and cinematography Mutant Mayhem was animated by
Mikros Animation in
Montreal and
Paris and
Cinesite in
Vancouver and Montreal. Mikros was hired in 2022 to handle the bulk of the animation, with Cinesite joining soon after to produce nearly 25 minutes. Mikros was one of many studios that completed a test shot for the feature. It featured 40 seconds of Donatello talking. The studio was tasked with matching the
CGI animation as closely as possible to the 2D reference provided. According to Mikros visual effects supervisor Matthieu Rouxel, Rowe told them, "If the picture looks like a 2D painting when it is not moving, that means we are good". The test helped Mikros realize the need to make specific developments to their rendering for the film: stylized shaders, curves, and edges. Mikros built a shader prototype using the toonshader of the
Autodesk Arnold render engine as a starter base. While the prototype was good for the test, the team knew they had to develop it further for the scale of a film. Rowe told the studio to avoid a "Photoshop filter feeling". The team realized the sophistication of the look and the need to be able to add graphic features to the lighting, "making it look as if they were painted one after another with different strokes". Mikros worked with Marcel Reinhard—the lead developer of shading, lighting, and rendering—to develop a shader that could isolate lights on the shading of objects and characters and give them special treatments. These treatments included scribbles,
cross-hatching, stepping, and color transitions. As the film's stylized CGI employs elements of 2D animation to achieve a sketchbook look, Cinesite's staffers, who had only had experience with CGI, had to quickly learn how to use 2D. To speed up the process, they sought out sequences and style guides from Mikros. Additionally, a group of five traditional 2D effects animators to train the team were assembled, and
Toon Boom Animation software was brought into their pipeline. Using these resources and tools, Cinesite developed internal animation tests, with regular feedback from Rowe on whether they matched Mikros' work. Kent Seki, head of cinematography, wanted to highlight the Turtles' youthfulness by keeping the camera close, handheld, and alive. He described it as being shot like "[you're] on the run" and used teenagers knack for getting into trouble as inspiration. To capture the Turtles as they engaged in antics both comedic and action, he adopted a
cinéma vérité style of filming, shaped by the works of
Emmanuel Lubezki and
Spike Jonze. Seki also sought to contrast Jonze's handheld style with a more formal camera language influenced by early
Paul Thomas Anderson and his cinematographer
Robert Elswit's work in
Boogie Nights (1997). When shooting scenes, they would alternate between these two different methods to present a dichotomy of the teenage world and the adult world: "So if the kids were being reprimanded by Splinter, [we] would be much steadier with the camerawork, and then when we cut back to the kids, they'd be a little bit more handheld, a little more loose, and those kinds of things started to creep into the cinematography."
Music In May 2023, it was announced that the score was composed by
Trent Reznor and
Atticus Ross, with Gabe Hilfer as music supervisor. The score album was released by Reznor's label, The Null Corporation on July 28, 2023.
Mutant Mayhem features hip-hop music from popular artists, with a heavy emphasis on classic
East Coast hip-hop to go with the film's setting. Many of the songs used in the films were ones that Rogen and Rowe would regularly listen to. An official playlist of some songs featured in the film was released on
Spotify. == Themes ==