This is actually the cover of a Sonic comic book that was for free comic book day, done by Tracy Yardley.
So apparently Tracy Yardley did the linework and someone named Matt Herms did the colors. I added the page containing the image on Matt Herm's deviantart account to source and removed the source_request tag, but I'm not sure how to resolve the Artist tag. The tag "matt_herms" exists, but I don't know what the convention is in cases like this.
