Teenage Mutant Ninja Turtles (also known as Teenage Mutant Hero Turtles in some regions) is an American animated television series produced by Fred Wolf Films and based on the comic book characters created by Kevin Eastman and Peter Laird. Set in New York City, the series follows the adventures of the eponymous Teenage Mutant Ninja Turtles and their allies as they battle the Shredder, Krang, and numerous other villains and criminals. The property was changed considerably from the darker-toned comics, to make it more suitable for children and families.

The pilot was shown during the week of December 28, 1987, in syndication as a five-part miniseries, and the show began its full-time run on October 1, 1988, and ended on November 2, 1996. The show was the first television appearance of the Teenage Mutant Ninja Turtles, and helped launch the characters into mainstream popularity, becoming one of the most popular animated series in television history. Action figures, breakfast cereals, plush toys, and other merchandise featuring the characters appeared on the market during the late 1980s and early 1990s and became top sellers worldwide. By 1990, the series was being shown daily on more than 125 television stations.

Characters from the show have been included in crossovers with later entries of the franchise, including the 2009 film Turtles Forever and recurring roles in the 2012 TV series for Nickelodeon.

Series overview

Seasons 1–7 The origins story in the 1987 television series deviates significantly from the original Mirage Studios comics. In this version, Splinter was formerly human, an honorable ninja master named Hamato Yoshi who studied art history as a hobby. He was banished from the Foot Clan (a Japanese dynasty of ninjas founded by one of his distant ancestorsTeenage Mutant Ninja Turtles 1987 series episode "The Legend of Koji") after one of his students, the power-hungry and seditious Oroku Saki (who resented Yoshi's leadership within the clan and aspired to usurp him), set him up for an offense against a visiting master sensei. Disgraced, Yoshi was forced to leave his native Japan and relocate to New York City, where he began living in the sewers with the rats as his only friends. Saki was given command of the Foot Clan, which he corrupted and transformed into a criminal organization.

Sometime later, Yoshi adopted four turtles after they were accidentally dropped into the sewers by a young boy named Chester Manley. He returned from his explorations around New York City one day to find the turtles covered with a strange glowing ooze. This substance caused the turtles, who were most recently exposed to Yoshi, to become humanoid, while Yoshi, who was most recently exposed to sewer rats, became a humanoid rat, and was given the name "Splinter" by the turtles. Yoshi raises the four turtles as his sons and trains them in the art of ninjitsu. He names them Leonardo, Donatello, Raphael and Michelangelo, after his favorite Italian Renaissance artists.Teenage Mutant Ninja Turtles 1987 series episode "Turtle Tracks"

Oroku Saki eventually leaves Japan and tracks Yoshi to New York City, where he intends to destroy him once and for all. It is also around this time that he begins working with Krang, a disembodied alien brain from Dimension X who ruled his native realm with an iron fist until he was stripped of his body and banished to Earth. Saki takes on a new pseudonym, "The Shredder", donning a suit covered with razor spikes, and complemented by a long purple cape, a metal samurai helmet, and a metal mask over his mouth.Teenage Mutant Ninja Turtles 1987 series episode "Enter the Shredder" Since leaving Japan, his ambitions have grown from usurping leadership of the Foot Clan to world domination. To this end, Krang provides the Shredder with a vast array of powerful technology from Dimension X, including the Technodrome, and funds most of his schemes throughout the series.

It becomes clear early on in the series that the mutagen which transformed the Turtles and Splinter into their new forms was dumped into the sewers by Shredder in an effort to murder Yoshi, as he had mistakenly believed it to be a deadly poison rather than a transformative agent. After several years of training under Splinter, the Turtles set out to find whoever is responsible for their transformation, and upon learning that Shredder was behind it, they vow to put an end to his ongoing criminal career and restore Splinter back to his human form. Along the way, they rescue and befriend Channel 6 news reporter April O'Neil, who becomes one of their strongest allies and later on her best friend Irma Langenstein. The Turtles, who had rarely left the sewers prior to meeting April, also began to take on the role of semi-vigilante crime fighters. Despite this, they frequently have to deal with citizens misunderstanding them, largely due to the efforts of Channel 6 newsmen Burne Thompson and Vernon Fenwick, who both distrust the Turtles and frequently and wrongfully blame them for the trouble that Shredder and Krang cause. As a result, they mainly have to rely on April (either via Turtle-com, or Channel 6 news reports) and her colleague and girlfriend Irma to inform them of crimes in the city, and to counteract Burne and Vernon's smear and bad-tempered campaigns against them with her own news coverage of the Turtles, portraying them as a force for good. Reluctant to expose themselves to the outside world, the Turtles initially wear disguises whenever they leave the sewers, although this is slowly relaxed as the series progresses and they gain the trust of the broader populace, whom they have saved from Shredder and other villains on many occasions.

Shredder, Krang, Bebop & Rocksteady, Baxter Stockman, and their legions of Foot soldiers repeatedly try to destroy the Turtles and take over the world. Much of their quest for world domination hinges on repowering Krang's mobile fortress, the Technodrome, and bringing it to the Earth's surface, as it was either buried deep under New York City (Season 1), stuck in Dimension X (Seasons 2 and 4), embedded in the Earth's core (Season 3), stranded in the Arctic (Season 5), or at the bottom of the Arctic Ocean (Seasons 6 and 7). However, their plans always fail, often landing the villains in humorous predicaments. Some episodes feature other minor villains, such as the Rat King, Leatherhead, Slash, General Traag and Granitor, and many others, or involve the TMNT getting themselves and the city out of a mess that they had inadvertently caused.

Season 7 marked a tonal and stylistic shift for the series. Compared to earlier seasons, The storytelling focused more heavily on action and adventure, moving away from the lighter, comedic tone that characterized much of the earlier syndicated episodes.

The season is notable for introducing a slightly darker atmosphere, while still retaining the humor and charm of the franchise. Many episodes in Season 7 continued to develop the overarching narrative involving the Turtles’ battle against Shredder and the Technodrome, culminating in a satisfying conclusion to several long-running story arcs.

Vacation in Europe Season 7 featured a "Vacation in Europe" side-season that took place during the fourth season where the Turtles, April, Splinter, and Irma win a vacation in Europe and end up fighting Shredder, Krang, and other villains across Europe.

Seasons 8–10 In the last three seasons, the show went through dramatic changes. The humor was toned down significantly, the animation became darker, the color of the sky in each episode was changed to a continuous, ominous dark-red sky (commonplace with newer action-oriented children's programming at the time), the theme song was changed, the introduction sequence added in clips from the first live-action film, and the show took on a darker, more action-oriented atmosphere, reminiscent to the original comics.Teenage Mutant Ninja Turtles 1987 series episode "Get Shredder" (These seasons are referred to as the "Red Sky seasons" or "Red Sky years" by fans.) The Turtles' demeanor evolved into a more serious and determined one than in prior seasons, and they devoted most of their time to tracking down villains. The series' main antagonists—Shredder, Krang, Bebop, and Rocksteady—who had previously been depicted as dangerous but comically inept villains, were now portrayed as a more menacing, unified threat. Additionally, Krang was revealed to have seized power in Dimension X through numerous betrayals and widespread destruction, resulting in old enemies seeking vengeance. Many recurring characters and villains were written out of the show by this point, with more focus placed on the main cast. The eighth season was also noted for the destruction of the Channel 6 building, which led to April working freelance.

At the end of the seventh season, the Turtles sent the Technodrome through a portal into Dimension X, but without Shredder, Krang, Bebop, and Rocksteady. As a result, the villains were stranded on Earth without any weapons or power, and were forced to work out of an old science building until they could find a way back into Dimension X to retrieve the Technodrome. The Turtles, taking advantage of the situation, pursue their arch enemies relentlessly in an effort to put an end to their schemes once and for all. Eventually, Shredder and Krang, along with Bebop and Rocksteady, build a new portal into Dimension X and reclaim the Technodrome, although the Turtles manage to track them down with the help of Gargon, a mutated resident of Dimension X who was being held prisoner by Shredder and Krang. At the end of Season 8, the TMNT finally banish Shredder, Krang, Bebop, and Rocksteady to Dimension X by destroying the Technodrome's engines and trans-dimensional portal, preventing them from returning to Earth.Teenage Mutant Ninja Turtles 1987 series episode "Turtle Trek"

From Season 9 onwards, Lord Dregg, an evil alien warlord from Dimension X, appeared as the new lead villain. He begins a propaganda campaign against the Turtles, turning the general population against them and in favor of him and his forces. Although Dregg is outed as a villain at the end of Season 9,Teenage Mutant Ninja Turtles 1987 series episode "Doomquest" the Turtles are never able to regain the trust of the broader population, due to an earlier smear campaign by Burne and Vernon that wrongfully blamed the Turtles for the destruction of the Channel 6 building. Additionally, the Turtles began to suffer from secondary mutations that temporarily transformed them into monstrous hulks with diminished intelligence, a problem that would not be completely resolved until Season 10. The TMNT also gain a new ally in the form of Carter, a brash African American male who initially sought out Master Splinter for training in ninjitsu, but is eventually exposed to mutagen and contracts an incurable mutation disease.