Davids, Brian (April 4, 2023). " 'Super Mario Bros. Movie' Star Seth Rogen on His Big Year of Animation and How 'Lion King' Influenced the 'Teenage Mutant Ninja Turtles' Process". The Hollywood Reporter. Archived from the original on April 5, 2023 . Retrieved April 5, 2023.

Lang, Brent (July 26, 2023). " 'Teenage Mutant Ninja Turtles: Mutant Mayhem' Sequel and Paramount+ Series in the Works (EXCLUSIVE)". Variety. Archived from the original on July 27, 2023 . Retrieved July 26, 2023. Francisco, Eric (July 20, 2023). "How Teenage Mutant Ninja Turtles: Mutant Mayhem Puts a Fresh Spin on the Franchise". Den of Geek. Archived from the original on July 22, 2023 . Retrieved July 22, 2023. Lambert, David. "Teenage Mutant Ninja Turtles - Formal Press Release for Vol. 11: Earth's Last Stand' ". TV Shows on DVD. Archived from the original on October 14, 2016 . Retrieved October 16, 2016.Rowe discussed the film at the Annecy International Animation Film Festival in June 2022, where a brief bit of animation was shown. Rafael Motamayor of /Film compared the film's visual aesthetic to Arcane, both having a "punk" style that he described as fun. [34] To accompany the title announcement in August 2022, a mural promoting the film went up in New York City. [58] In December 2022, PeaTos and Paramount Consumer Products announced that PeaTos' Crunchy Pizza Rings would feature Mutant Mayhem branding in a promotion timed to the film's release. [59]

During a battle with the turtles, Karai is informed of her true nature by Leonardo (who has developed a crush on her since season 1), but she is too reluctant to accept it. When she is taken to the lair, she finally realizes the truth and disowns Shredder, who responds by imprisoning her. Repeated attempts to free Karai ultimately succeed, but Shredder captures her again and uses her as bait to kill the Hamato Clan. However, Karai ends up transforming into an albino horned viper, much to everyone's horror. Teenage Mutant Ninja Turtles - Volume 7". TV Shows on DVD. March 10, 2014. Archived from the original on July 17, 2015 . Retrieved July 16, 2015. Pitts, Lan (July 13, 2023). "Ninja Turtles: Mutant Mayhem Early Fan Screenings Announced". GameSpot. Archived from the original on July 20, 2023 . Retrieved July 13, 2023. Croll, Ben; Hopewell, John (April 27, 2023). " 'Ninja Turtles,' 'Spider-Verse,' 'Nimona,' and Growing Anime Influence Mark Boisterous Annecy Animation Festival Lineup". Variety. Archived from the original on April 27, 2023 . Retrieved April 27, 2023.

a b " Teenage Mutant Ninja Turtles: Mutant Mayhem – Financial Information". The Numbers. Nash Information Services, LLC . Retrieved October 22, 2023.

In response to this, Shredder has the Foot Clan help the Kraang, who have just perfected the previously unstable mutagen, launch a second invasion of New York, starting by destroying the turtles' lair courtesy of April's friend Irma, who was really an elite Kraang spy named Kraang Subprime, and forcing them to abandon it. The Kraang begin mutating New York's populace, including Kirby, despite the efforts of Earth's military and the turtles. Leonardo is gravely wounded when he is ambushed by the entire Foot, and Splinter is seemingly killed during a battle with Shredder. The turtles, April, and Casey are forced to flee to the O'Neil family's summer home in Upstate New York as the Kraang successfully conquers Manhattan. Milligan, Mercedes (March 6, 2023). "Teaser: A New Generation of Heroes Comes Out of Their Shells in 'Teenage Mutant Ninja Turtles: Mutant Mayhem'!". Animation Magazine. Archived from the original on March 10, 2023 . Retrieved April 4, 2023.Zarghami, Cyma (2012). "Cyma Zarghami interview" (Interview). Archived from the original on January 13, 2020.