There are parasites even other aberrations avoid. The deadly cerebug is one of them. Resembling fat, eyeless fleas about the size of a large domestic cat, their speckled, coppery brown exoskeletons tend to glint in the light when exposed, which is a rare thing. Possessing four forelegs ending in sharp barbs, they are avid diggers propelled by two strong and larger rear legs.
Perpetually hungry for new brains to feed upon, and almost always buried below the surface of the ground or within cave walls and ceilings, these foul creatures always try to strike with surprise to find a new host. Bodies of its former hosts may even be found nearby as a lure, still wearing or carrying what treasure they had in life. The cerebug cares not for trinkets, only for the fresh brains of the warm blooded.
Cerebugs always seek to bury themselves near populated areas of warm blooded creatures, picking off stragglers. Once they find a host, the cerebug uses that host to lure new victims away. If the host body begins to decay, they abandon it and burrow into a nearby surface, using the dead body as a lure for predators or the curious, only to begin the process over again.
Cerebugs have several small burrowing claws used to dig through earthen materials, including softer stones like shale, slate and limestone. They cannot burrow through metals harder than lead. They dig through bone and chiton like it were earth beneath their tiny legs.
Cerebugs, once hatched from their clutch, scatter to the four winds. They stake out territorial hunting grounds with which to find prey. They do not suffer the presence of other cerebugs. If two meet in the same given territory, whether they are in a host or not, the two fight to the death to control the area. This behavior is likely the only reason these parasites have not grasped more territory or endangered larger populations.