There is a helicopter which regularly (1 to 5Xs a month) at night or day flies very low & fast, has flown over a vehicle, playing a chasing game down neighbor's driveway and down the road. Who can I report this to as it also has spooked pets and wildlife?
The question as it stands now is asking one thing in the headline, and the other in the body. I'll answer the latter.
In any case of public disturbance your first point of contact is the police. If the disturbance is acute, you may call emergency number (depending on your location 911, 112 or something else).
You may also find out what is the aviation authority in your country, and contact them.
For both, I bet finding contact information by google takes less than a minute, so it will be quicker that writing this answer was.