The Leech Zombie is a human corpse infested with leeches infected with the Tyrant virus.During the Raccoon City Destruction Incident, a vast amount of leeches within and around the Raccoon General Hospital became infected with "t". Along with increasing their size, aggressiveness, and giving them a collective consciousness, the virus imbued them with another insidious method of infection: the ability to infest and control a human. The leeches swarm over a human in vast numbers, attach themselves to every orifice and exposed section above the knee, suck the victim of all their blood, and, through some unknown means, presumably by manipulating the victim's nervous system, take complete control of the body as a host. This entity is the Leech Zombie.The Leech Zombie was a horrific and disgusting creation. His insatiable hunger for blood, a consequence of the leeches controlling him, was his sole driving force. If a bloodied prey was within the company of healthy prey, he would ignore them and focus solely on the wounded one, as well if large amounts of blood were present in the form of a blood pack, the Leech Zombie would lap it up until every drop was gone.
The Leech Man used the ventilation system to move throughout the rooms, and would enter through a vent cover in the ceiling. The leeches formed an invincible shield around the host, making it impossible for physical damage to do anything but temporarily weaken it. Also, gunfire was extremely ineffective, doing less damage to it than a tackle. Though it was essentially just a cadaver with leeches, the Leech zombie was significantly stronger than any normal Zombie .
Leech zombies should not be confused with the Mimicry Marcus, which are individual masses of leeches who assume a humanoid shape.