Teenage Mutant Ninja Turtles: Mutant Mayhem (2023)

Agents from the Techno Cosmic Research Institute move through an apartment building in New York, hunting Dr. Baxter Stockman, who has been developing a mutagenic serum. They break into his lab while Baxter speaks to a mutated housefly he created. The fly attacks the intruders, tearing through the agents; one operative, reacting in panic, strikes a nearby chemical canister with a torch, igniting it. The resulting explosion kills Baxter instantly and destroys the apartment. In the aftermath, the mutagen spills into a stairwell and runs down into the city sewer system, carried by water and grime; the sole mutant fly escapes into the night.

Fifteen years later, four anthropomorphic turtles live beneath Manhattan with the rat who adopts them as their father and teacher. Splinter trains them in ninjutsu and strict secrecy; he forbids them from mingling with surface dwellers, recounting how, when he first appeared on the streets as an ordinary rat, humans only despised and feared him. The turtles -- Leonardo, Donatello, Michelangelo, and Raphael -- have grown into teenagers in both size and temperament. They slide across rooftops in the dark to steal groceries, vault between fire escapes and use ninja stars to cut open sealed produce bags, then pause on a rooftop to watch an outdoor screening of Ferris Bueller's Day Off. The brothers laugh and long aloud for a place among humans, but Splinter presses the danger of exposure and insists they remain hidden.

One night, while practicing on a rooftop and experimenting with throwing stars, the brothers slip. A projectile whistles down and strikes a girl on the street; her helmet absorbs the impact and she is unharmed, but her scooter is stolen by a passing thief. Leonardo chases the thief despite his siblings' protests. The pursuit leads the turtles into a warehouse where a network of thieves fences stolen goods. The turtles burst into the stacked crates, springing from beams and using kata and weapons to disarm and incapacitate the gang: Leonardo parries and cuts a gun from a man's hand with his katana, Raphael uses his sais to pin a goon against a pillar, Donatello topples a stack of crates onto two thieves with a staff strike, and Michelangelo improvises with a skateboard to knock a henchman off balance. Their assault incapacitates the gang without killing them and they recover the stolen scooter. April O'Neil arrives at the warehouse to claim her property, sees the turtles, and freezes. She watches as the four mutate figures lower their hoods and reveal themselves; rather than flee, she offers them pizza and records an impromptu interview with her phone, asking about their origin and giving the turtles a chance to speak in plain terms about where they came from. April tells them she is an aspiring reporter trying to recover from an on-air vomiting incident that made her the subject of ridicule. She reveals her investigation into a series of thefts involving TCRI equipment and a criminal known only as Superfly, and she gives the turtles her number: she believes exposing Superfly will win hearts, and she suggests working together to change public perception of mutants.

The turtles accept her proposition. They want to perform visible good deeds to become seen as heroes, and Donatello gleans data from intercepted henchmen that narrows Superfly's operations. A TCRI truck transporting vials of retro-mutagen travels the streets under heavy security when a group of criminals hijacks it. Police pursue; in the chaos Superfly swoops in, seizes the payload from the truck, and executes the henchmen who were working with him to secure the mutagen, leaving the mutagen in his hands. From surveillance footage April shows the turtles, they learn the thief is himself a mutant who wears a flylike motif.

April sneaks the turtles into her high school so they can observe human teenagers and gain allies. They infiltrate classrooms and hallways, experiencing moments of acceptance along with awkwardness. April helps the turtles gather more leads. A night-time rendezvous under the Brooklyn Bridge turns into a confrontation: a group of mutants assembles, and Superfly reveals himself. He stands larger and more charismatic than expected and greets the turtles as family, introducing his inner circle: Bebop and Rocksteady, brash and triumphant; Wingnut and Leatherhead; Ray Fillet and Genghis Frog; Mondo Gecko and Scumbug; and others who recall being created by Baxter Stockman. Superfly claims he raised them, that Baxter is their maker, and that they are siblings bonded by shared exile. He invites the turtles to join them at a nearby alley bowling alley, where the mutants relax and bond. Michelangelo flirts and befriends Mondo over their mutual love of laid-back living and pranks; Raphael and Bebop test each other's toughness; Donatello speaks science with Ray Fillet; Leonardo listens intently as Superfly explains his history.

In the dim light of the bowling alley, Superfly lays out his plan: he has accumulated enough TCRI technology and the stolen retro-mutagen to create a device that will aerosolize the mutagen and blanket the atmosphere, forcing an evolution where animals mutate into dominant beings and humans become subordinate or subdued. He claims that humanity's cruelty justifies the reversal of power. The turtles recoil; Leonardo rejects the plan outright, arguing that hurting innocents cannot make them more than monsters. Superfly responds to their refusal with coercion -- he implies violence for defiance -- and the turtles attempt a strategic escape. Leatherhead, Wingnut, and Rocksteady pile into a van to drive away with their equipment; Donatello uses his bo staff to strike the vehicle's accelerator, sending it careening and hurling the mutants through the windshield so the turtles can commandeer the van and race toward Superfly's hidden lair. Superfly intercepts them, slamming through the van in a violent confrontation and beating the turtles until he regains control of the mutagen. Before the turtles can prevent it, TCRI operatives arrive and seize the turtles, leaving the stolen mutagen in Superfly's possession.

At TCRI headquarters, Cynthia Utrom oversees the containment lab. She interrogates the turtles and orders technicians to extract their mutagenic material, siphoning samples in a process she calls "milking" to gather DNA and mutagen for study and weaponization. Microscopic tubes siphon fluorescent liquid from the turtles' wounds; Leonardo struggles against restraints, Raphael screams as needles pierce his skin, and Michelangelo and Donatello groan as their strength ebbs. Cynthia's objective is to synthesize hybrid super-soldiers and control mutations. While the technicians operate, Splinter arrives at TCRI: he bursts through doors and corridors in a calculated rampage, striking guards with precise martial strikes, toppling computers with a tail-sweep and overturning centrifuges. He incapacitates Cynthia's security team with a series of rapid strikes and frees his sons. As they flee the facility, Splinter scolds them for disobeying orders and reminding them that darkness and exposure invite danger; he hauls them into the sewer and patches their wounds, emphasizing his belief that the surface is unsafe. The boys listen but remain restless: they desire friendship, school, and the chance to be judged for their actions rather than their appearance.

Superfly retreats to his lair and rigs a device capable of dispersing mutagen across the city. The turtles, April, and Splinter locate his machine in an abandoned industrial plant beside a river. Superfly activates the apparatus as the mutants squabble over whether to push their plan forward. Leonardo speaks to Bebop, Rocksteady, and the others, appealing to their dignity and reminding them that resorting to cruelty will mirror the worst of humanity. The mutants waver; they express their own pain from being ostracized and their wish to be treated with respect rather than to enact vengeance. Superfly, increasingly desperate to force his vision into reality, attempts to complete the sequence alone. The turtles and the other mutants spring at him to stop the activation. During the scuffle a containment vessel ruptures and a stream of mutagen spills into the river. Superfly lunges into the liquid to retrieve his device and becomes drenched. The mutagen does not simply coat him; it bonds with his physiology and with aquatic life. The fluid saturates fish and the water's surface, and Superfly fuses with sea creatures and debris. He mutates into an enormous, insectile-beast -- a colossal fly-like kaiju that combines organic segments, marine bulk, and mechanized appendages. As he rises from the water, he slams onto the dock and storms toward the city, smashing cranes and hurling cars, his limbs crushing anything in reach.

Cynthia watches the unfolding chaos and orders the city declared under martial alert. News helicopters flood the air. Reporters mistake the mutant coalition and the turtles for the aggressors and air footage that frames the turtles in silhouettes beside Superfly's rampage. The public perceives the turtles as part of the monster attack and responds with fear. Leonardo assembles his brothers atop a collapsing rooftop and tells them they must act not to win popular approval but because preventing harm is the right action. Raphael grits his teeth and accepts a leadership that demands restraint; Donatello begins devising a technical solution; Michelangelo improvises weapons from street debris. Donatello concludes that a TCRI retro-mutagen serum can reverse the effect if it reaches the creature's primary intake; he identifies a vulnerable blowhole-like cavity in the kaiju's head that receives airborne intake. The plan requires someone to acquire an intact vial of retro-mutagen from TCRI and launch it into the creature's inhalation point.

April, forced into a newsroom as helicopter-mounted cameras sweep the skyline, takes the anchor desk live when anchors flee. Her hands shake, but she drives the feed, telling the city that the turtles and the other mutants are trying to save people and that New Yorkers should help rather than panic. She broadcasts the turtles' call for assistance and reveals where the creature will next rampage, urging citizens to support the mutants who are fighting for the city's safety. Splinter prepares to deliver the serum himself, crouching and leaping through alleys toward the kaiju while Donatello and Michelangelo coordinate with human volunteers who answer April's plea. The turtles scale buildings, distract the beast and battle its smaller fused appendages: Leonardo slices through tendons anchoring a fused lion to the creature; Raphael uses a wrecking bar to pry away a fused elephant tusk; Michelangelo triggers an overturned crane to drop a net over a fused tiger; Donatello maneuvers a hydrogen tank to blast distracting flames away from civilians. Splinter reaches the kaiju and attempts to administer the serum directly, but Superfly bats him aside with a massive limb, sending him tumbling across several blocks.

As Splinter lies dazed, a man emerges from rubble and grabs him, hauling him to safety. That man's action prompts others to move: a group of New Yorkers forms a chain to return the serum that had been delivered to the turtles' staging point but obstructed by debris. They pass the vials hand-to-hand across sidewalks, over overturned cars and across makeshift bridges of scaffolding until Donatello receives the canister. In the meantime the kaiju fuses with animals from a zoo and a nearby aquarium, swallowing whole giraffes and sealing owls into its carapace; these merged creatures begin to turn the kaiju into an even larger and more grotesque amalgam. Donatello, splintered concentration and device in hand, times a leap with Leonardo and Michelangelo. Leonardo slices open a tendon near the nasal cavity. Michelangelo catches the serum with a slingshot improvised from a billboard, and Donatello launches the retro-mutagen straight into the creature's blowhole. The liquid vanishes into its throat.

Within moments, the fused animals within the kaiju begin to decouple. Giraffes slide out and run free; whales and fish break away and flounder back toward the river. The monstrous mass that is Superfly shrinks and constricts as the mutative bonds sever. Fur and barnacles slough off and animals break into panicked flight to their original habitats. The remaining mass compresses into a single, ordinary housefly that drops onto a lamppost. People who had stood terrified now cheer and applaud as the city recognizes the turtles and the mutants as the ones who protected them. New Yorkers help clear rubble, pull survivors from wreckage, and carry stretchers. April remains on air and narrates the city's change in perception, calmly describing the turtles' role in saving lives and appealing for compassion.

In the immediate aftermath, the group returns to the sewers. Splinter allows several of the mutant allies to take refuge there: Bebop and Rocksteady, Ray Fillet, Mondo Gecko, Genghis Frog, Wingnut, Leatherhead, and Scumbug accept his hospitality and settle into the tunnels. Splinter and Scumbug begin an unlikely relationship, sharing quiet moments that make the turtles recoil in embarrassment but which Splinter regards as companionship. Cynthia Utrom, meanwhile, secures the shriveled remnant of Superfly -- the de-mutated housefly -- placing it in a specialized containment jar and recording data. Rather than celebrate, Utrom's expression hardens as she reviews footage of the turtles' escape; schematics of new devices appear on her screen. She makes a call to an unseen contact, requesting "the one who can find them," and a clipped voice agrees to bring in an operative known to be relentless: the Shredder.

The turtles take tentative steps toward integration with human society. Splinter enrolls them in April's high school. Leonardo, Donatello, Michelangelo, and Raphael arrive in civvies and move through the cafeteria, the bell rings, and students at first stare but then react with curiosity and acceptance. Donatello starts a computer club in a classroom, teaching classmates to code; Raphael joins the wrestling team, training beneath bright gymnasium lights; Michelangelo enrolls in an improvisation class, breaking the ice with humor; Leonardo helps April research TCRI's missing records and the surveillance footage linking Cynthia to Baxter Stockman's old lab. The turtles attend prom with April as a guest, and they stand beneath streamers and a banner that reads "Celebrate" as friends cheer and take pictures. They smile and share awkward teenage dances; Splinter and Scumbug sit together nearby, holding hands over a bowl of punch.

As the credits move, scenes show the turtles adjusting to school routines: Donatello opens a door to a room full of computers and names the club; Raph pins an opponent on the wrestling mat and raises his arms; Mikey improvises onstage to applause; Leo and April sift through TCRI files in a dimmed library, their faces lit by the glow of a laptop. Cynthia Utrom observes the celebrations remotely from a darkened office, her gaze fixed on a wall of monitors. She lifts the jar containing the de-mutated Superfly and stores it on a shelf beside other specimens. Her finger taps a secure line, and she recruits the Shredder -- an armored, menacing operative whose reputation for cruelty precedes him -- to retrieve the turtles. Above ground, the city now knows the names Leonardo, Donatello, Michelangelo, and Raphael; below ground, the turtles sleep in their lair, their mouths still smelling of pizza, unaware that a new threat is already being dispatched to hunt them. The final image holds on Cynthia's resolute face, then cuts to black.

At the end of Teenage Mutant Ninja Turtles: Mutant Mayhem (2023), the Turtles and their allies defeat the villain Superfly after he mutates into a giant monster threatening New York City. April O'Neil overcomes her anxiety and publicly reveals the truth, rallying the citizens of New York to support the Turtles. Using an antidote, they revert Superfly back to a normal fly, and the Turtles are accepted by society. The film closes with the Turtles starting high school, signaling a new chapter in their lives.

The ending unfolds with the Turtles, their father Splinter, and a group of mutants confronting Superfly, who has become a massive kaiju-like creature after falling into the river during their battle. Initially, Superfly's plan was to mutate all animals to overthrow humans, fueled by his hatred for mankind. The Turtles and mutants fight him fiercely, but the battle escalates as Superfly grows larger and more destructive.

Meanwhile, April O'Neil, who has struggled with anxiety and public speaking throughout the film, manages to overcome her fears. She interrupts live news broadcasts that are condemning the Turtles for the chaos, explaining the true story behind Superfly's rampage and the Turtles' efforts to stop him. Her courageous public statement shifts public opinion, and the citizens of New York begin to support the Turtles rather than fear them.

Donatello discovers that Superfly's blowhole contains a large amount of mutagen. The Turtles seize this opportunity and drop a canister of anti-ooze into the blowhole, which reverses Superfly's mutation and returns him to his original fly form. This act effectively ends the threat to the city.

After the battle, the Turtles are accepted by society as heroes rather than outcasts. The film concludes with the four brothers starting high school together, symbolizing their integration into human society and the beginning of a new phase in their lives.

Regarding the main characters' fates:

• Leonardo, Raphael, Donatello, and Michelangelo: They successfully defeat Superfly and are embraced by the city. They begin attending high school, indicating their growth and acceptance.
• Splinter: He witnesses the humans helping his sons and begins to see the good in mankind, moving away from his earlier distrust.
• April O'Neil: She overcomes her anxiety, becomes a credible reporter by telling the truth on live TV, and plays a crucial role in uniting the city to help defeat Superfly.
• Superfly: After mutating into a giant monster and causing destruction, he is reverted to a normal fly by the Turtles' antidote and presumably neutralized as a threat.

The story ends on a hopeful note, emphasizing themes of acceptance, overcoming fear, and the possibility of coexistence between mutants and humans.

Teenage Mutant Ninja Turtles: Mutant Mayhem (2023) does not have a traditional post-credits scene after all the credits roll, but it features an important mid-credits scene that serves a similar purpose in teasing the future of the franchise.

This mid-credits sequence is split into two parts:

1. Montage of the Turtles' High School Life: It shows Leonardo, Raphael, Donatello, and Michelangelo adjusting to life as high school students at Eastman High. They try out for activities like musicals, skateboarding, and attend prom, highlighting their integration into normal society after their heroic actions.

2. Introduction of the Villain Shredder: The scene then shifts to April O'Neil and Leonardo investigating the shady organization TCRI, which is behind the mutants. The sequence ends with Cynthia Utrom, a character spying on the turtles, ordering her henchman to "Bring me the Shredder." The iconic villain Shredder is shown in a non-speaking cameo, silhouetted against the New York City skyline, signaling his return as a major antagonist in the sequel.

This mid-credits scene is crucial for world-building and sets up the next chapter in the TMNT saga, confirming that Shredder will be the big bad in the upcoming sequel. There is no additional scene after the credits themselves.

Baxter Stockman is revealed as the creator of the mutagen (ooze) that transformed the turtles and other mutants in Teenage Mutant Ninja Turtles: Mutant Mayhem.

When the turtles meet Superfly's gang, they discover a kinship as mutants and end up bonding by participating in bowling and playing arcade games together, highlighting their connection despite opposing goals.

April O'Neil, an aspiring reporter, helps the turtles by recording their heroics and eventually hijacking a news report to tell the public that the turtles are good and trying to defeat Superfly, which helps change human perception and gain their support.

The turtles feel guilt and conflict when confronted with other mutants who plan to destroy humanity; they sympathize with the mutants' reasoning but ultimately choose to do the right thing and protect humans, reflecting their struggle between kinship and morality.

After the main events, Raphael joins the wrestling team to channel his rage, Donatello geeks out in the computer club, Michelangelo participates in the improv group, and Leonardo continues investigating the Techno Cosmic Research Institute with April, showing their growth and integration into normal teenage life.

Teenage Mutant Ninja Turtles: Mutant Mayhem (2023) is rated PG and is generally family-friendly, suitable for children with some parental guidance due to certain content.

Potentially objectionable or upsetting aspects for children or sensitive viewers include:

• Sequences of violence and action: There are many fights involving mutants and humans, with weapons used that cause characters to be knocked unconscious or wounded. Some property damage occurs during these action scenes.
• Language and impolite material: The film contains some strong language and impolite expressions, though nothing excessively harsh for a PG rating.
• Mild sexual content: There is a kiss and discussions of romantic attraction, but these are brief and mild.
• Arguments and tension: Several arguments and moments of conflict occur among characters, which might be intense for very sensitive viewers.

Overall, the movie balances action, humor, and emotional moments with a vibrant, stylized animation that appeals to both kids and adults. Parents of younger or sensitive children might want to be aware of the moderate cartoon violence and some language before viewing.