Light Foes are a kind of enemy that usually appear as a mob during your journey in Infernium.
These bad guys can be destroyed using the Flash Light. To do that, just approach them and start lighting them with your Flash Light. You will see how their head slowly sucks in their body until they completely vanish.
If you light them with the flashlight but you stop lighting them they won't regain health. Also, when you light them they slow down. This is really useful for mob control.
They can be found in a lot of environments in Infernium, especially in New Game +. The most common places to find them are at Darkness. You will have a painful time killing and hunting them in the caves and especially in the Underground Lake Arena.