Board Thread:Questions and Answers/@comment-4779545-20150830070304/@comment-995426-20150830230300

Suspects: Or, of course, they could be recycling more scripts from season 1 and it'll just be Baxter Stockman again.
 * , trying to have Donatello all to herself again.
 * , who's been tricked into believing is gone and is being manipulated into bringing an ancient Japanese demon to life because he's convinced he's bringing Splinter back to life in a giant glass jar.
 * The Dream Beavers, looking for a purpose again.
 * The Finger, for reasons we'll never understand.
 * Fong, trying to make a name for himself after being ousted as leader.
 * Carlos Chiang O'Brien Gambe, who wants to make the news rather than just report it.
 * Hamato Yūta, trying to track down his elusive son and grandchildren.
 * Joan Grody, who never really believed Muckman's claim that there are no mutant turtles.
 * , and he'll mutate into Tokka this episode.
 * , now sentient.
 * That who swapped bodies with Raphael in Plan 10, who was somehow left behind when the Kraang were mass-teleported back to Dimension X.
 * Jack J. Kurtzman, who was really always a operative helping to clear out the Kraang in preparation for a Triceraton invasion.
 * Sir Malachi, out of more desperate boredom.
 * Mr. Murakami, because the turtles forgot to pay their check once.
 * Kraang Subprime, because why not?
 * The Little Girl, so she can have another teatime with Leonardo where he can't get away. Her name will be Dale Evans McGillicutty.
 * The Pizza Guy, tired of the main characters randomly screwing him over. His name will be Vernon Fenwick.
 * An older version of getting revenge on a younger Michelangelo for cheating her in a future divorce because their relationship had no depth or substance to begin with.
 * The Squirrelanoids.
 * The Squirrelanoids.

Also, kudos if you already realized that most of this post is just me messing around. :)