Teefury

It's so obvious I can't believe someone hasn't done it before...LOVE IT!

Smooth it out and you've got a winner, I personally wouldn't get it but I know plenty of people who would!

I would buy this in a heartbeat. Not a fan of the green though. Personally I woulda made the green blue, and then make the Oods jacket blue as well.
It does need to be refined though a little bit

tried it with a more subtle background:

I love it! I'm a Whovian and I'm just starting to get into Pokémon and I would so buy this! But maybe play around with the colours. You should make his jacket/vest thing blue so it resembles Ash a bit more (if that doesn't go over your colour limit of course) and work on the background to make it a bit more aesthetically pleasing.