Parasite
In the Old World, one of the largest and most conservative categories of large pathogens,
unlike microscopic pathogens such as bacteria and viruses, parasites tend to be larger and maintain their autonomy and independence.
Bacteria like Dead Plague Fog State Bacteria, Quadruple Spherococcus, or viruses like Mad Shell Virus, Blood Plague Virus, etc., upon infecting an individual, form a complete entity, namely the "Patient."
There is no such thing as a separate discussion of the "host" and the "pathogen."
Parasites are different; most of them can be included in the macroscopic world, and some mutated super-sized mimicry parasites can move freely like humans.
Mahat J. Nash, a current deputy actor of the Fear Circus, is such a super-sized Amoeba Brain Worm, directly mimicking a human's appearance, without the need for parasitic infection and even much stronger than his kin.
Parasites greatly value their autonomy,
