50 feet (in Kraangdroid)
Kraang Prime was the leader of The Kraang and the overarching antagonist of the entire series, being the final antagonist of season 1, one of the two main antagonists of season 2, and with the other being Shredder, the overarching antagonist of season 3 and the posthumous overarching antagonist of seasons 4 and 5. Ever since his death, the Kraang no longer exist.
Kraang Prime was once an Utrom scientist named Kraang until he eventually discovered the Mutagen from the Kraathatrogon worm. He became deranged and used his psychic powers to turn millions of Utroms into slave copies of himself, forming the Kraang since and changed his name to Kraang Prime. Although not much is known about his past, Kraang Prime seems determined to terra-form the Earth to turn it into another Dimension X. Yet, according to Kurtzman, he's been trying to achieve this objective for years.
Showdown: Kraang Prime successfully managed to capture April O'Neil and attempted to use her mental energy to take over the world. He was defeated by Leo and was trapped on the ocean floor inside of the Technodrome.
Plan 10: He was talking to the Kraang about mind swapping Kraang's mind with a human's.
The Invasion: Kraang Prime began his second attempt at taking over earth and successfully managed to take over New York City and drive out the Turtles and their allies. His robotic body was taken down by the Turtle Mech. But the Kraang succeeded and New York was taken over.
Annihilation Earth! Part 1: Kraang Prime is inside the Technodrome, waiting for Kraang Subprime to get it up and running. Kraang Prime is furious and begins to rush his fellow comrade in order to get it up and running.
The Technodrome then gets targetted by the Triceraton mothership and aimed at with its built-in Devastator machine. It is then centered in the middle of the Technodrome and unleashed, killing both Kraang Prime and his fellow friend, Kraang Subprime.
Kraang Prime resembles most others of his species, except that he is much larger; over 10 feet in diameter. He also has three hexagonal decorations on his forehead. When needed he can move about in his custom built robot body. The body is a massive 25 foot mechanical weapon with long tentacle-like arms and a powerful energy weapon mounted on the head. It is much larger and more powerful than any other Kraangdroid. Kraang Prime speaks English without the aid of his mechanical body and is not as redundant in his speech as other Kraang are, though he does lapse into it at times.
- "KRAANG HAS WAITED A LOOOONNNG TIME."
- "The invasion that is known as the invasion of Earth begins...NOW!"
- "Like all Kraang, I am called Kraang, but you can call me Kraang."
- "Kraang came all this way for you...April O'Neil."
- "Soon your world will be ours!"
- "Kraang will not be stopped by pathetic mutants!!"
- "There's nowhere for you to run, MUTANTS!"
- "All of you will DIE here!"
- "What!? Intruders!"
- "KRAANG, I AM SPEAKING TO KRAANG!!!"
- "The Turtles?!"
- "You will all suffer!"