Eyeball

Eyeball
The eyeball is a quick and small mob that is more scared of you than you are of him. Because of this, he get's really scared and starts running around when he hits you and when you hit him. They automatically gain night vision in the night if the moon stands correct.

Drops
The eyeballs drop lenses. When they have the night vision potion on them, they drop a night vision lens instead. While these drops are not common, they're not super rare. Looting will increase the chance of getting one by about 10% per level, though one eyeball will never drop more than 1 lens