The turtles, Groundchuck and Dirtbag are taken to Shellri-La by an alien "Turtleoid" named Kerma. Kerma seeks help from the turtles to defend his planet from a two-headed dragon named Herman the Horrible.
The turtles unmask the dragon as they prove that the menacing creature is actually operated by two renegade Turtleoid delegates. Kerma return the turtles back to Earth, where they destroy Shredder's new Technodrome Mark II and afterwards defeat Chrome Dome.
This is the first appearances of Kerma, Groundchuck, Dirtbag, and Chrome Drome.
The special Primetime 1 hour of the Teenage Mutant Ninja Turtles is on Saturday, August 31, 1991. Episodes #125 and #126 originally ran as a 1 hour prime-time special titled "Planet of the Turtleoids". And reran, it was split into 2 parts on Saturday Morning on October 26, 1991 here on CBS. And this is the season finale of the Teenage Mutant Ninja Turtles. See you in the next season in fall of 1992.