Sonic is on project x zone? On spriters resourse theres all sprites from the game already, u could download his sheet for a better comparison
he's not. the image is fake.
Funny thing about this is that I was dumb enough in the past to actually believe this when I saw that image about a year probably before PXZ came out (don't remember when I saw this image, so I'm throwing guesses).
For advice on spriting, take a look at these tutorials (since you said that "you're fairly new at shading", I thought these might help; not sure if you looked at them, though):
Also, if you're aiming for a PXZ styled sprite, I suggest looking at PXZ sprites on the Spriters Resource or the sprites of its predecessor, Namco x Capcom (like what Ramza said). Look at the dA galleries of other pixel artists and see their attempts. This is kinda how I learned to shade sprites.
Good luck, and I hope I've been helpful.
This is a generic forum signature.