Cephalos appears as long, centipede-like parasites with a spiked bone protruding from its spine, which can be used as a weapon.
Cephalo grows larger in size when their host Majini's head has been seriously damaged or destroyed, breaking through the neck to defend the rest of the host body. At this point they take complete control of the body's function, acting as a replacement brain. Unlike the Spanish Plaga, they were based on Type 2 Plaga forms such as Cephalo are more resistant to sunlight and may be encountered outside at daytime.[excerpt 1]
Cephalos are incredibly resilient to gunfire. Since most of the body is outside of the host when they come out, further damage to the host body does little to stop it.