Kraang are alien robots from another dimention. These robots speek human and have brains in their chests.
This mysterious fluid is called Mutagine, a substance of medamorfessis. Like the Kraang, it is from another dimention. It also has mysterious powers.
One drop of the Mutagine could transform you into a mutant.
Even though the Kraang robot body is defeated, there is still the alien brain to deal with.
AAAAAHH!
BLAH!
The location of the Kraang is the Big Apple. Not the fruit apple, I mean New York.
The only ones who can stop the Kraang from their plan to begin the planetary mutation are Mato Yoshi and his turtle sons, the Teenage Mutant Ninja Turtles.