Weird, I had a nightmare that ended like that too, but after watching the Pokemon movie "The Rise of Darkrai." Maybe games/anime with Darkrai in them are...possessed or something? Well, not really, but supposedly if you're transfixed on something too much, people say it starts to affect your dreams...
I was running through some mud bear-footed on holiday. It was near a beach and the tide was going out, so we rolled in the mud for a bit XD
Anywho, after we got on the rocks, I stared at my foot and the mud eerily made the shape of a Palkia. Not very detailed, but it had the main shape.
Sometimes I look at colorless images and momentarily see them as pokemon. As for the darkrai idea, it reminds me of the time where may attacked me in my dreams after I had been reading a star wars graphic novel for half an hour (in fact, pokemon characters always appear in my dreams with characters from sic-fi movies. Weird).