Devilcish are the first in a family of toothed horrors known as the Diablocephidae, or "Devil heads". Devilcish themselves are facultative ectoparasites, using their large rows of cartilaginous teeth on their four "jaws" to take chunks of flesh out of their victims, leaving behind characteristic "X" shaped wounds. They have been in an evolutionary arms race with the Devorators, evolving stronger teeth and jaws in order to combat the armor plating of these creatures. Devilcish also target other, smaller ectoparasites, consuming them whole.
While these savage creatures certainly live up to their name, they also have another side to them. Devilcish, in order to combat the armor of some of their prey and locate the weak spots of others, on the whole have become some of the smartest Cish yet to evolve. Most Devilcish have social habits and tend to hunt in groups of 3-5, with the largest Devilcish being the leader. Young Devilcish are more developed than their contemporaries, being able to feed straight after getting out of the egg.