"I dreamt that it was night and that I was lying in bed. (My bed stood with its foot towards the window; in front of the window there was a row of old walnut trees. I know it was winter when I had the dream, and night-time.) Suddenly the window opened of its own accord, and I was terrified to see that some white wolves were sitting on the big walnut tree in front of the window. There were six or seven of them. The wolves were quite white, and looked more like foxes or sheep-dogs, for they had big tails like foxes and they had their ears pricked like dogs when they pay attention to something. In great terror, evidently of being eaten up by the wolves, I screamed and woke up. My nurse hurried to my bed, to see what had happened to me. It took quite a long while before I was convinced that it had only been a dream; I had had such a clear and life-like picture of the window opening and the wolves sitting on the tree. At last I grew quieter, felt as though I had escaped from some danger, and went to sleep again." (Freud 1918)

http://en.wikipedia.org/wiki/Sergei_Pankejeff