An idea I had, it's probably been done but I'm going to do it anyway.
The rules are simple. One person posts a concept, and the next makes a fakemon based on that concept. You can be as detailed as you like, but the minimum required is a name, typing and brief appearance description. Once you do that, you post your own concept and the next poster makes a fakemon based on that.
I'll start with an easy one: a Jack O'Lantern-based fakemon. --- "The greatest pleasure in life is doing what people say you can't do." ~Walter Bagehot