Wisps!

Courtesy of @Ruko for the eyeless Gastly base and the concept; basically, he came up with an idea of a wisp-like Pokemon that could change type depending on the type of the first two moves it knows. Naturally, this means that all 18 types could be represented, plus any and all type combinations of the lot. As a way to differentiate each of the types, he thought it would be a cute idea for the main body/head to be one color and the wispy particles in the back to be another, so there we go.

The faces, of course, are just there to be cute.

When I actually have the time and energy, the wisps will probably get an actual shape to them that isn't just being a Gastly; for example, a water/electric type wisp might be a water droplet with electricity-like wisps coming out of it, but for now this is what we have and I think it's cute enough to post here.

In order: Bug/Psychic, Fighting/Dragon, Electric/Dark, and Ice/Poison.