Within the context of the show, King Kai's planet is found in "Other World" a kind of afterlife in the Dragon Ball Universe that most characters arrive at after they die. The planet is first introduced when the series Main Character Goku Dies and is allowed by King Yemma (the king of hell) to meet and train with King Kai. Later in the series King Kias planet becomes of place of training not only for Goku but other characters as well. Despite the planet's size the gravity there is significantly heavier than normal, which has some metaphorical weight for fans, but in the context of the show is valuable to a lot of the characters for training.
The most obvious feature of the planet is how small it is, in spite of the size though King Kais planet does support a lot of plant life. There are a few fruit-bearing trees that dot the surface as well as some white flowers that spring up among low cropped grass. The planet is bisected by a single road, which King Kai drives around from time to time for leisure. There's also a small house on the planet shaped kind of like an igloo as well as a nearby garage that houses a red Chevy. The most interesting feature of the planet to me is the space that it sits within. From certain angles, you can see the tail end of snake way (the means of arriving to the planet) but beyond that space is empty of any other structures or heavenly bodies. There's a truly bare void that’s to one side of the planet and a plain of rolling clouds that’s to the opposite side. Because of the size of the planet the orientation of the clouds to empty sky changes quickly. Where in one scene the empty sky was above and the clouds were below, in the immediate next scene the clouds might be above or even vertically oriented to the empty sky. There are three permanent inhabitants on King Kias Planet. King Kai himself a rotund deity, and then his two pets, the Monkey Bubbles and the Grasshopper Gregory, all of whom are adjusted to the intense gravity.
The planet is a vibrant green and it sits kind of in the center of the two other planes that rotate around it. On one side are rolling golden clouds (maybe this is where the nimbus Goku rides comes from) and on the other is a purple void. King Kai's house and garage are made out of a kind of dull gold or yellow brick and his Chevy is a bright red.
Resonance: A Strange Afterlife and The Gravity of Isolation
There are two major things that resonate with me about King Kia's planet. The first is it’s relationship to a conventional western understanding of what the afterlife is like and heaven in particular. In the beginning of the series characters can only get to King Kai’s planet by dying (later in the show this kind of changes). Combined with the fact that within the context of show Otherworld is where most of the deities in Dragon Ball live, it's clear that this is definitely supposed to be a kind of spiritual dimension as pose to something like a remote, alien place. In descriptive terms Otherworld sound kind of like a conventional afterlife. People die, meet deities who judge them and are then relocated to various places, like heaven or hell. But in terms of the visual character of Other World, and King Kai's planet in particular, the design is completely foreign from a western idea of heaven. The traditional western idea is a place filled with milky white clouds, which sit beneath pearly gates adorned with gold and open upon streets paved with jewels. But on King Kai's planet, there is only one road and it’s pretty regular. Even the planet itself is ordinary, discounting the small size and the intense gravity. But the most interesting part to me is the space the planet is located in. It’s an empty void where golden clouds sit to one side and a purple void exist on the other. There are other things as well like the constant change in orientation so that it's hard to ever say what's up or down, but I think that kind of strangeness gives King Kai’s planet a gravitas for novelty alone.