S02E01 - Return of the Shredder
Synopsis
Just when the Turtles believe themselves rid of Shredder, tin-grin is able to persuade Krang to return him to Earth.
As an excuse to see Shredder suffer for his incompetence on earth last time, Krang strips his ally of all weapons and footsoldiers; He's on his own this time!
Using the trans-dimensional portal to return, Shredder quickly reunites with Baxter Stockman, and recruits a local ninja school to disguise themselves as the half-shelled heroes so as to keep them busy long enough for him to kidnap Splinter.