Split off from the chunky knightworm, the thornant, already being able to consume crystal flora, developed the ability to eat other “worms”. It developed a chitinous growth on its tongue, which together with a hooked mouth forms a sort of “beak”. With these features, alongside the development of “claws” on its legs, it can catch and kill struggling prey, as well as bite off defensive features such as spikes. This also makes it better able to eat crystal flora, because the sharp points can pierce the shell instead of needing to scrape away at it. Its body is a bit more slender in comparison to its size, making it a bit faster. It stays close to the sea floor, but its fins, now enlarged, can give it a short boost of speed to catch a potential meal.
Like its ancestor, the thornant reproduces sexually and lays thousands of eggs. However, it has also developed mating conflicts—males will fight one another using spikes placed on either side of their respective gonopodium, and sometimes females will prevent males they find unfit from mating with them using those very same spikes.