The foi-devourer sauceback split from its ancestor the shell-crushing sauceback and shrank to half its size. Its tusks lengthened and its heads mobility has increased to allow them to impale their foi prey with ease. Their feathers have became short and fuzzy to lower the need for hygiene as they wade through their boggy home. Their hooves have spread out to give a larger base while the actual pieces have thinned to lower drag when hunting in the water, their legs have lengthened, and the feathers that line the hooves have become whisker-like and sensitive to movements in the water to give them a better idea of where to strike. Along the back ridge of their tail are vestigial snorkel bristles from their larval stage. They are more social than their ancestors, males have a small group (2 or 3) of females that he defends and interacts with, they mate for life. The females lay their eggs on the edges of the water, although the eggs often become submerged by the time they are ready to hatch.
The larvae of the foi-devourer sauceback are aquatic, when hatched they wriggle into the water and unravel their thousands of breathing snorkels along the backs of their tails. The larvae live, look, and move in the water much like a mosquito larva. They filter feed and tend to gather into large groups, usually just as a result from best feeding waters. As they develop their limbs and tusks they go through an awkward stage in which they begin attempting to hunt foi, often a youngster will be found vainly trying to wrestle an adult mohawk foi into submission.