The Bacteria monster is a long, black humanoid entity made from the wires of the ceiling of level 0.
Bacteria entities are very dangerous and preys on all humans and entities that it encounters.

Once The Bacteria finishes eating the insides of a person, they will inject from its claws a weird

bacteria (The Microscopical one of course) that will infect the rests of the insides forever and mutate

them to transform into a bacteria monster, hence the name.

Habitat

Bacteria monsters are exclusive to Level 0 of the backrooms and does not appear in any other level.