The Krang Brother is one of the two secondary antagonists (alongside Krang Two) of Nickelodeon's 38th non-theatrical film, Rise of the Teenage Mutant Ninja Turtles: The Movie.
He is the brother of the Krang Leader and Krang Sister who seeks to aid them in conquering the universe for his kind.
Vote which fictional character would naturally fit in-universe with a big-named franchise! No time-travel, no interdimensional crap, no "Pooh's Adventures", they would just exist in-universe.