Killow is a major antagonist in the Ninjago franchise, serving as one of the secondary antagonists of Season 9, a major antagonist in Season 10, a minor character in Season 11 and a supporting character in season 15.
He was the general of the Sons of Garmadon who acted as a figure head for the group's true leader and an inmate in Kryptarium prison. He joined the cult that worshiped Garmadon, claiming he was the savior of Ninjago City after he defeated the Great Devourer with the four Golden Weapons of Spinjitzu. The group successfully resurrected Garmadon but only his Oni side. Starting in "Big Trouble, Little Ninjago", Killow, Ultra Violet and the Sons of Garmadon terrorized the citizens of Ninjago as Garmadon ruled with an iron fist.
After Lord Garmadon's defeat at the hands of his son, Lloyd Garmadon, Killow was thrown in Kryptarium Prison, where he kept his anger in check by painting all day and gave little trouble to the people in impairment. During the Crystal Apocalypse, killow helped the Ninja defeat the Overlord, the true culprit behind the Great Devourer's attack.