The fourth season of Teenage Mutant Ninja Turtles began airing on Nickelodeon on October 25, 2015. On June 17, 2014, Nickelodeon ordered a fourth season of Teenage Mutant Ninja Turtles.
fter last appearing in the season 2 episodes, The Manhattan Project and Wormquake!, the 1987 counterparts of the turtles will have a crossover episode with the turtles from this series. In addition with Cam Clarke, Rob Paulsen, Townsend Coleman and Barry Gordon reprising their roles from the episodes, Pat Fraley will also reprise his role as Krang from the original series.
After the Turtles, April, and Casey are saved from the destruction of Earth, the Fugitoid uses his spacecraft the Ulixes to turn back time to six months earlier in order for him and the Turtles to prevent the Triceraton Empire from assembling the three components of the Heart of Darkness that are scattered throughout the universe before everything on Earth is lost. Besides fighting the Triceratons, the Turtles also face new enemies in outer space like Lord Vringath Dregg of the planet Sectoid and the bounty hunter Armaggon.