The killcoat split from its ancestor when some fuzzcoats migrated into the Mae Volcanic region due to over-competition in their home biomes. The harshness of the environment and lack of flora prompted the killcoat to become completely carnivorous towards the Glacial Sauceback, doubling in size to tackle the bigger prey. Once it gained success in the volcanic region, it began to spread out to the other regions of Drake, where it preys on the local loafshells, though it has to be careful of their venomous sting.
It has wooden hooves to provide better treading on the rocky landscapes. Like its ancestor it has fuzzy "fur" on its body. However these filaments grow longer around its butt-nostril to prevent particles of ash and dust from entering its lungs; the nostril itself can be voluntarily sealed to prevent breathing toxic gases from eruptions.
Their tongue has become more of a trunk-like appendage which is unable to be retracted into the mouth. A mucus membrane prevents the skin from getting caked with dirt. When hunting, they will use the electricity in their tongues to paralyze prey and their fangs to inflict wounds. They've developed palate-teeth inside their mouths to help grind up food for digestion. They prefer to ambush their sauceback prey and have learned to go for either the head or the tail-lungs.
They live in groups or "bandits" of 4-5 consisting of a male/female couple and their 2-3 young. They live for about 10 years. Females take 5 months to gestate the young, who themselves take 2 years to mature and will stay with their parents for 3 years after that; the young are tasked with tracking down saucebacks and leading their parents to the potential meal. When a male leaves his family, he will live for 1 year alone, hunting until he kills the biggest sauceback he can find. He will then carry the skull from this kill and seek out a prospective female to whom he will present said skull; if she accepts it then they will mate for life.