The buzzer is an enemy from Hacx. It is a dangerous floating robot with spikes on the lower side of its body.
The buzzer's only method of attack is to use its spikes to hurt the player. It has 175 hit points, and since it can float, it can be hard to shake off. It is still somewhat fragile and can be taken down easily by most weapons. When they attack in large numbers, it is best to take a safe distance as they can easily overwhelm and defeat the player.
When a buzzer dies, it explodes like a barrel, capable of damaging anything near it. It is recommended to always finish them off at a distance, since a large amount of damage will be taken otherwise.
There is a variant of the buzzer known as stealth. This variant behaves just like the buzzer, with the only differences being that it is partially invisible and has 30 hit points. The stealth can spell trouble for a surprised player, as even a single tazer shot is enough to make it explode (likely in the player's face).