The planet K'ai, although outwardly primitive, has remnants of long-forgotten high technology and sorcery. Its people are green-skinned and for the most part blonde haired, but otherwise human.
The Hulk appeared in K'ai during an attack of the warthos and drove the huge monsters away. When the people came out to greet him, the Hulk was startled because they are green-skinned, like him and that they welcomed him rather than running away. Becoming the legend and savior of K’ai, the Hulk also commenced an infamous relationship with Queen Jarella of K'ai. She led him into the city and called on her sorcerers to help the Hulk learn their language. The spell succeeded and also allowed the human personality of Bruce Banner to emerge in the Hulk's body. The Hulk and Jarella fell in love, defeated Visis, who was seeking to usurp their leadership, and seemed destined to live happily ever after. Unfortunately destiny in the form of a supervillain named Psyklop interfered and snatched the Hulk away from K'ai.