Zombies (Clock Tower)

"Getting infected with the Cerebral Toxin turns you into a Zombie... The bacteria forms a new, parasitic brain... and makes the old brain stop functioning..."

- Bates reading about the virus. "That means the zombies' weak point is their parasitic brain... I've got to try!"

- Bates before encountering a zombie. The Zombies are the supporting antagonists and the common stalkers of the 1998 spin-off videogame Clock Tower 2: The Struggle Within. They are test subjects infected with Cerebral Toxin, as the bacteria forms a new, parasitic brain and kills off their true brain; resulting in becoming zombies.

History
The zombies were patients send to George Maxwell from the director, Henry Kaplan of the Memorial Hospital to the Memorial Pharmaceuticals Research Lab as test subjects for Maxwell's Cerebral Toxin plan. Maxwell got infected by the toxin and went crazy, Maxwell released the zombies from the lab and possibly the whole city.

clock tower 2: the struggle within
Alyssa wakes up in Memorial Hospital where Alex Corey explains that he took both her and Stephanie there after getting a call from Kathryn. A man's scream interrupts them, and he goes outside to check, leaving Alyssa alone in the room.

Alyssa begins to encounter zombies as she explores, in addition to hearing a mysterious female voice in certain places.

Alyssa finds nurse Jessica Cook hiding in the storage closet, but is only able to get any information out of her with Bates. She tells him the information on the zombies is in her office, and he goes there to discover that the zombies' weak points are their parasitic brains.

Alyssa attempts to escape out the back door, but finds it locked. Alex appears and shoots it open with his pistol, and a crowd of zombies attempt to get inside. Alyssa then faints to the ground as he kills each of them with a shotgun.

Outside, Alyssa and Alex are seen watching the building in flames. She laments over her adoptive father's death, claiming she should have died instead. Alex states that it's not like she died there once already, and claims he has to leave in order to take care of the remaining zombies. Alyssa looks up and smiles. During this scene, Bates' voice can be heard whispering, "I'm not going to die!"

Presumably all the zombies are dead from the hospital, the Lab, and the city.

Trivia

 * The zombies are the only known stalkers in the Clock Tower series to exist in massive numbers.
 * In general, zombies are the most common enemies in survival horror.