I gotta say, I love how you really made it look like a Godzilla poster. A lot of people would have just drawn Gonzo with some vague dinosaur-like plates on his back, but no, yours REALLY look like Godzilla's back plates. And the scale over the skyscrapers is right too!
Now I'll have fun speculating how this came to be.
Perhaps this is just another one of Gonzo's weird dreams. Or maybe it's an experiment of Bunsen and Beaker's gone horribly wrong. Or maybe some anti-alien government agents tried to recapture Gonzo, and triggered some self-defense transformation, like the Iron Giant.