Your avatar is cool. :o It looks like an creature that would be a small enemy. And then maybe later in a stage the grey version would pop out and be huge. That'd be the boss fight.
I don't have a wii u anymore to test it myself, but if homebrews are not visible on the wii u menu I think you can press L + R + minus to open the plugin menu, there should be an option called "homebrews on wii u menu" or something similar