Nyantolo secreted a sticky substance on their backs, which attracted insects and swamp debris. This accumulated and hardened into an irregular carapace with many hollow chambers. In addition to camouflaging the creature, a nyantolo could use breathing tubes in its back to blow air through the carapace, producing an eerie moaning whistle. Older nyantolo had larger carapaces, and thus louder songs which would attract more mates. Nyantolo had three sexes, and mated communally, laying eggs three weeks later. The wailing of dozens of nyantolo during mating season was described as maddening.
Nyantolo ignored one another completely outside of mating season. Over their two to five year lifespan, they would stake out a feeding ground, drifting or slowly swimming through the swamps, and shoveling swamp debris and small fish into their jaws. In addition to allowing food to cross their path by chance, two of the five known subspecies secreted an oily fluid from glands in their mouths. This fluid attracted small fish and croator, an avian species which was also found in the swamps. Finally, if a larger being came too close, they moved surprisingly swiftly, attacking with their flippers and their beaks.
The nyantolo were named for Nyantolo, an unfortunate Rodian scout who came across one by accident. After one of the creatures killed him, the species was named in his honor. Visitors to Wyndigal 2 were thereafter cautioned against disturbing the swamp beasts.