Bujack (バジャック, Bajakku) is one of the kaiju in SSSS.GRIDMAN. It is the sixth kaiju created by Akane. Its purpose was to entrap the Gridman Alliance in a dream world. It was the monster of the week for Episode 9.
Bujack looks like a cross between the plesiosaur and dragon. It has black body and yellowish underside, along with multicolored striations all over the upper body. The entire underside of the creature is mechanical, and it has a pair of insectoid wings acting as the source of its dream-inducing powers.
Bujack can induce others to sleep so that they have a dream where everything seems perfect and normal. This only works as long as the wings of the avatar of itself within its victims' dreams remains intact. In the real world, when the kaiju employs the dream-inducing power, it becomes intangible, unable to either be attacked or to interact with its surroundings. The only way to force Bujack to materialize and free its victims at the same time is by entering one of the victims' dreams and tear the kaiju's avatar's wing off.
Because of its primary purpose, the kaiju is not very powerful in real life. Its only means of attack is projecting green lightning blasts from its mouth, although it's argued that the kaiju would be capable of close quarter combat with its tail. The reason why it was defeated easily by Powered Zenon was the result of both being ambushed and its weaker combat capabilities.
The kaiju was found by the Neon Genesis High School Students floating above the city. It was incorporeal, thus protected from harm, so the NGJHS had to wait. Inside the dreamworlds created by the kaiju, Yuta, Rikka, and Utsumi slowly came to realize that they were in a dream, and rejected Akane's offer to stay. This gave Gridman the chance to attack the dreamworld version of the kaiju, making it vulnerable in the real world. The NGJHS then mobilized and combined to form Powered Zenon, and swiftly defeated the kaiju on their own, without Gridman.