|Introduced in||"Susan Strong"|
The Hyooman tribe (referred to by Jake as Fish People) first appears in "Susan Strong." They are a primitive race of mutant humanoids who, like Finn, wear uniquely animal-themed hats. They are rather paranoid and speak in strange verses. After Susan discovers the Candy Kingdom, they threaten to eat the entire kingdom and all of its inhabitants (except Peppermint Butler) because Susan discovered candy was delicious. Nearly all Hyoomans have what appear to be gills and fins on their heads, revealing that the Hyoomans are not human, but in fact mutants, a realization that greatly disappoints Finn. In the original storyboard, the hatch to the Hyoomans' home has "Biohazard Danger" printed on it, although this does not appear in the final cut of the episode. Unlike the rest of the Hyooman Tribe, Susan does not remove her hat at the end of the story; the possibility of her being human remains in the air.
Although the Hyoomans tried to eat the Candy People, when Finn encounters them again in "Beautopia" he insists that they deserve to be helped as much as anyone else because they are just misguided. Jake on the other hand insists that they are just creepy "fish people" and didn't know if they could still be trusted. Nonetheless, the duo helps to save them from the Lub Glubs. As Susan Strong explains, long ago the Hyooman Tribe lived in a mysterious fallout shelter-like habitat located deeper within the underground sewer complex, which they call "Beautopia." Finn and Jake helped drive out the Lub Glubs with fire (which the Hyoomans are also terrified of), and they moved out of the garbage heaps and back into their old buildings.
The Hyoomans' home is located underground which can be accessed by a hatch in the ground.
The area is extremely large and the majority appears to be water.
Hyoomans range from very short to tall and appear anatomically identical to humans, other than their fish-like heads, which feature scales, fins, and sometimes gills which could be caused by the nuclear fallout that irradiated the land that is now Ooo. They dress in primitive garments and accessories. Each member of the Hyooman Tribe wears an animal hat, which hides the distinctly non-human features of their heads.
- Finn teaches the Hyoomans various words when he still thinks they are human; they become known as Hyooman after the way they mispronounce "human."
- The animal hats on the Hyoomans' heads at first identify them with Finn, who also wears an animal hat; however, the hats ultimately prove to have been foreshadowing the Hyoomans' false appearances.
- They appear to speak a dialect of English.