King Kai is a character from the popular anime and manga series Dragon Ball. He is known as the North Kai and resides on a small planet located at the end of the universe. King Kai is responsible for training powerful fighters and overseeing the North Galaxy. He has a distinct appearance, characterized by his blue skin, antennae, and a jovial personality. King Kai is famous for his unique training methods, which often involve unconventional tasks and challenges. He is also the one who introduced Goku to the Kaio-ken technique and the Spirit Bomb, both of which are essential skills in Goku's battles against formidable foes.