These mutated germs were the most excellent hunters. They climbed to the roof of buildings or a hidden corner of the street and assimilated themselves just enough into their environments. In fact, some of them could even change their colors to disguise themselves as stairs, carpets, or any other mundane things.
Being suddenly ambushed by these monsters was impossible for anyone to defend against, their only possible outcome would be to helplessly become food.
Because of this, the only countermeasure against these monsters was to discover them ahead of time.
That would not be very hard in the beginning, as the monsters weren't used to their environments, but the longer they lived, the better they would become at hunting until they could perfectly blend into their surroundings.
The ground could be a monster, a door could be a monster, a car could be a monster, even the streetlights could be monsters.
