Shadow man!

Hi guys, my mother has been seeing a dark figure who looks like a man at 6 feet tall. He always is in the same spot and bends over on one side like he is looking at my mother and my mother screams ever time this happens after she gets out of dreaming. However, she is able to move unlike sleep paralysis, plus she is very vividly. This happened again last night which is why I am trying to get to the bottom of it. She has been seeing this figure just shortly after my father passed away. My mother saw my father however far more clearly and was able to see his actual face which she knew it was my father (her husband), and he was a younger version of him before he got sick with his heart disease. What could this figure be?. Is it my father or some other entity?. This figure however is not trying to harm her but it's annoying as it keeps happening. This doesn't happen every night but it has happened numerous times over the last eight years.The figure disappears as soon as my mother screams sometimes other times it disappears without her doing anything at all. My father passed away back on July 25, 2010 so just about 8 years old.I am really not sure what is going on here.