Voracious parasite

Voracious paraites, otherwise called internal parisites, are a sub-class of creatures created by Doctor Silverton in the fictional story of Slayer. At first they appear as tiny fleshy pills that are swallowed by "hosts" and grow to the size of footballs. When activated by remote control the pod hatches and the creature destroys the host's insides, bursting out of their mouth and sometimes even leaving their host to cause chaos. This monsters appearance in both of the Slayer movies probably contributes to their MA15+ rating.