King Kai (Kaio meaning, “King of the Worlds”) or North Kai (Kita no Kaio meaning, “North King of the Worlds” or simply “North Kaio”) is a protagonist in the Dragon Ball series. He is the ruler of the North Galaxy, a deity, Goku’s mentor and former martial arts tutor. He also taught Tien Shinhan, Chiaotzu, Piccolo and Yamcha martial arts.
He always appear on Teashade sunglasses and possesses a short stature. He owns a 1957 Chevrolet Bel Air Hardtop that is red in color and has a pair of antennae that looks like that of a cricket. He is known to consistently have psychic discussions with beings across the universe.
King Kai is a Dragon Ball character with an enormous sense of humor such that you must make him laugh before he trains you, he also cracks bad jokes. He is a very intelligent character and a store of wisdom, skill and technique. That is why he has an awesome knowledge of the universe which makes him specialize in universal telepathic links. He exhibited his skill in planning and strategizing during the Frieza Saga.
King Kai is also a valuable mentor and a skillful martial artist. His training methods in martial arts appear strange to his student as he applies strange techniques in his training method. The first two tasks of his training involve hitting Gregory with a hammer (his butler cricket sprite) and catching Bubble (his pet monkey).
He was born on Plant Kaishin and went to live on his planet as soon as he became a Kai. His planet is located in the Other World at the end of the Snake Way. He lives with Gregory (a motor-mouth grasshopper) and Bubbles (a monkey) and spends a lot of time contemplating the heavens, seeing how far he can pee and counting the blades of grass. He also teaches special skills like Kaio-ken and Spirit Bomb to visitors. His planet used to be over 100 times its current size but it was destroyed by Beerus (The God of destruction). Beerus destroyed the planet because he lost to King Kai in a car racing video game. King Kai had to take a large fragment of his shattered planet, made it spherical in shape and built a road to ease driving. He also defeated and imprisoned Bojack and his crew in a star. He trained Goku after his death in a battle with Raditz.