Kabumpo is the elegant elephant, a resident of Pumperdink, one of the more notable random kingdoms shoved into Oz somewhere. Pompa, the prince of Pumperdink, is required to marry a fairy princess, so he and Kabumpo head to the Emerald City to get his bone on with Ozma.
That's not what this comic is about. This comic is about how, meanwhile, the exiled Nome King turns into a giant and gets the entire Emerald City stuck on his head like a goofy stone hat. The residents of the city are understandably in a panic about this, except for the Wizard. He assures the masses that everything will be fine. Then the Wizard promptly vanishes, as he's wont to do, because the Wizard is a jerk.