The Ghost Busters should have came and took care of Ghost. The Ghost had no right to come and tell Hamlet that. It's not Hamlets responsibility to do such a thing. If he was a true father then he wouldn't have told his son and filled him with such bad things.
The voracious green ghost that passes through walls and leaves slime behind is known as Slimer, although he was never referred to by name in the first Ghostbusters movie. Description from grahamsdownunderthoughts.blogspot.com. I searched for this on bing.com/images