Butterfish are bizarre, amphibious detritivores that live in tide pools and intertidal zones. They are scavengers and prey animals, feeding on beached fish and rotten kelp; the bacteria and mold from these materials then fuel the poison glands all over the creature's slimy skin. This poison is an alkaloid compound and is lethal to ingest, aside from larger or poison-immune predators such as Voidwalkers. Their bright, clashing coloration indeed warns of this poison, and this combined with their sheer abundance on the shores of Planet Chroma has ensured their survival despite the lack of ability the Butterfish has to combat predators.
When entering the water, butterfish move their six fins as if they were insect wings, leading to their name. They do not posses gills, but also do not need to surface or leave the water for air; they directly siphon oxygen from the water around them through their skin. They are euryhaline animals, meaning that they can survive in water regardless of its salinity; however, they prefer coastal ocean water. The species can be found anywhere from the seafloor to river deltas to muddy ponds and is beginning to be considered a pest by researchers. There is hope for detoxing and using it as a food source; Voidwalkers, when asked, describe the taste of butterfish as "pleasantly thick, once one gets past the slime".