Player encounters creatures ("enemies") that one would normally expect to attack the player character outright, but these do not. Instead, they might even talk to you and leave you alone.
Alternate name: Friendly monsters
The first video game about Neutral monsters was released on October 1991.
This does not include temporary neutrality nor neutrality that you can't avoid disrupting.
Player may "accidentally" attack and kill these due to appearing like regular opponents from a distance.