|“||Krang 1: Kraang. The ones in this place are not in this place where they were.
Krang 2: The ones are called Turtles, Kraang. They are dangerous to what we are doing in this place and other places.
Krang 1: Yes. I have knowledge of that. The Turtles must be eliminated from all places.
|~ The Kraang vowing to eliminate the Ninja Turtles.|
The Kraang are an alien species that act as the central antagonistic faction of the 2012 Teenage Mutant Ninja Turtles TV series, serving as the central antagonistic faction of Season 1, one of the two main antagonistic factions (alongside the Foot Clan) of Season 2, the secondary antagonistic faction of Season 3, one of the two secondary antagonistic factions (alongside the Vreen) of Season 4 and a posthumous antagonistic faction in Season 5 (appearing as the main antagonistic faction of "Lone Rats and Cubs").
The Kraang are a homage to Krang and the Utroms. It is later revealed that they used to be a majority of the latter species' population before being brainwashed by Kraang Prime into becoming mindless copies of himself after going mad with power when he mutated himself.
They were involved in the creation of the mutagen that turned the titular main protagonists into mutants. They launched invasions on New York in the finales to Season 1 and Season 2, managing to succeed in taking over the city in the latter. The turtles and the Mighty Mutanimals managed to banish the Kraang to their home dimension half way into Season 3 for good and any remaining Kraang, including Prime and Subprime, were killed off by the Triceratons.
They reappear in Season 4 in "War for Dimension X" and "Trans-Dimensional Turtles", however, nothing about their position and fate changed because both of these episodes took place after the turtles time traveled, and the episodes themselves mostly took place in Dimension X.
All of the Kraang are voiced by Nolan North, who ironically voiced Raphael in TMNT (2007).
Origin and background
It was stated by the Queen Utrom in "War for Dimension X" that the Kraang were once peaceful Utroms themselves, however, they were mind controlled and enslaved by the power hungry scientist Kraang (who soon started calling himself Kraang Prime) and turned into mindless and emotionless virtual copies of himself. The Kraang would later engage the Triceratons in a massive war for control over Dimension X, they would later win the war when they used Zayton Honeycutt's energy source, renaming it "The Black Hole Generator", to obliterate the Triceraton's home planet. The Kraang would spent the next several thousand years trying to mutate worlds and universes to look like theirs, although they never succeeded because their mutagen was not perfected and only mutated people into the last thing they touched (normally animals or plants). The Kraang were also responsible for mutating primates into humans, injecting April's mother with Kraang DNA while she was pregnant, giving April her psychic powers, and accidentally mutating Hamato Yoshi and his pet turtles into Splinter, Leonardo, Donatello, Raphael and Michelangelo.
In the series, The Kraang are multi-tentacled brain-creatures who claimd to have come to Earth a millennia ago from another dimension to colonize it. Unfortunately for them, the Earth’s biosphere is not particularly hospitable to them, so they’re plotting to transform the Earth’s environment into something more suitable for their own kind – and destroy all human life! They brought the Mutagen Ooze with them from their own dimension, but it doesn't work as they thought it would, as the physical laws of our world are different from their own.
They have been kidnapping scientists to help them modify it ever since. It has been revealed that it was the Kraang who were responsible for Splinter and the Turtles' mutation. The Kraang breathe a noxious gas that is toxic to humans and other Earthly life. Their ultimate goal is to mutate the entire planet using the mutagen and the Kraang-like powers of the Turtle's closest friend and Donatello's love interest, April O'Neil, whose mother and great-grandfather they experimented on before she was born. That way the Earth would become habitable for them and nothing else.
The Kraang, as a whole, are highly malevolent. Throughout the series, they commit various acts of theft, kidnapping, and terrorism to get their way. They also are rather clueless regarding Earth culture as only the likes of Prime and Sub-Prime speak fluent English. Despite this, they are highly crafty as their tech as mentioned by several characters, is far superior to that of Earth. That said, some beings like Donatello, are capable of using their technology or at least sabotage it.
Fortunately, but the time of the season 3 finale (and Season 4 episode "Earth's Last Stand" in the alternate timeline), Kraang Prime, along with Kraang Subprime, were killed by the Triceratons, who wanted to destroy Earth to rid the Kraang from Earth by destroying it, also due to that even without mutagen, they basically harmed it. With Prime gone, all the Utroms who were brainwashed into becoming Kraang regained their individual personalities and returned back to Dimension X.