I love this. I'm too old for Pokemon, but I've always been familiar with the characters and the designs. The idea of merging them with Tim Burton, who has such a distinctive monster style of his own, makes so much sense I wonder if someone did it earlier than this.
If so, too bad! This is the one I saw first. These sketches are by Vaughn Pinpin, but if you told me they were by Burton I would completely and totally believe you. These are my faves, but there are more at Pinpin's blog.
Thanks to Mark for the link.