I've discovered that, whenever I'm bored, I have a list of specific episodes from a ranging from a variety of TV series that I automatically go to. So, here is a very long list of my favorite episodes.
During this episode, Arthur finds a magic horn that lets him talk to his dead father, Uther, but accidentally releases his father's ghost onto Camelot. Or at least that's what Gauis says the problem is. But I don't think that was Uther's ghost.