The bogey-man is a consciousness of pure fear, and is created in reaction to fear itself. The more people fear something, the more energy they put into it, and the more powerful it becomes.

The consciousness of the Bogey-man coalesces as disparate parts, much like a hollow skin is filled with rats and similar, except is has no skin to contain the parts in.

Example: Suppose a village fears terribly a particular band of Goblins, the Bogeyman will coalesce those goblins and anything that supports them as their overarching superconsciousness. He can speak through any of them, make them move in concert, but he himself cannot be attacked by simply attacking those goblins, becuase he can simply expel the one you attack from his control. Wiping them all out does nothing but increase the fear, because they might come back, or there might be others. He could also still continue to exist in and use their animals, or the inanimate objects in their village or encampment. Imagine wiping out the goblin encampment only to find a note that reads "And yet I remain."

Those under the influence of the bogeyman do not know it. Accusations that they are under his influence will sound insane to them. eg: "What are you talking about?! I'm just taking safety precautions!"

If the fear is particularly concentrated on one individual, he can take the form of a phantom version of that individual. example: the phantom image and voice of Raithev Sris.

If your reaction to one of his incarnations makes you particularly feared (eg: you wipe out an entire race because of your fear of them and the bogeyman's influence over them, and now other similar races fear you), you risk coming under his influence.