Why am i seeing and hearing things from the same ghost/demon type thing

when i was in about 5th or 6th grade, i used to see this demon type thing at night, no matter how dark or bright it was. it would keep me from sleeping and scare me to the point where i would get light headed and almost faint. it would only appear when im not looking at it, as if it was trying to sneak up on me, and when i see through the corner of my eyes, it would snap my head in his direction and after a few moments it would be gone. it had a long black robe with a hood to cover his face, but i could still see non detail characteristics, like black spots for eyes and very sharp teeth. its hands were very old and had a greenish hue as if they were from a dead body, with very long nails. every time i saw it, it would be charging at me like it wants to hurt me. it would call at me and taunt me, and every morning i would wake up with mild blood on my sheets and burning cuts on my forearms. and now its back, and this time my dog (a Labrador) can sense it too. it doesn't appear as often but i think it tries to talk to me. i calls my name almost every day in a very sly, whispering voice. but it says it very fast as if its in a hurry or passing by me very fast, but every time i hear it, i don't see it, and vise verse. how bad is this? does anyone know why?

I am always skeptical when a person describes details like "sharp teeth" , "hooded robe" and "green hands" on an entity they claim to have seen. That's not to say I don't believe you, but rather, that I have never experienced anything like that nor seen photos of demons with that much detail. That said, more information is needed, otherwise all anyone can do is speculate.

Do you still live in the same house you lived in when you were a kid? If so, there could be some natural, explainable reasons for what you are seeing. The first would be a simple case of EMF. Bad wiring (or poorly shielded wiring) , cell towers and high power lines are all causes of electromagnetic fields. If you are especially sensitive to EMF, then you could be hallucinating. The specific form this hallucination takes could have been inspired by scary stories, a movie you saw when you were little, or even a halloween costume. Your dog would also be sensitive to EMF. Dogs are often more sensitive to a lot of natural phenomena than humans are.