Excellent Job
For a guy just practicing different styles, constantly re-envisioning himself in different art styles, this came out pretty good. Even if it was just practice, everything clicked together.
Now, when you suggested what kinds of styles to incorporate into a "Finished Version", you're asking the wrong guy. You should never have asked me, because I want artists to push themselves above and beyond what they're comfortable with.
Okay, first off: Rick Marin is a Newgrounds artist. You know him from the Primal War series and the latest one, G.I.N.A., and that's a pretty hard order. An anthropomorphic animal you with realistic if beefy proportions is what I'd look for, although he does ordinary humans pretty well, too.
Another guy I'd vie to top is The Shadman. Why? Because he's just insane. In addition to emulating his art style, try capturing his subject matter for just a moment (nothing totally gory or sexual, but that is part of his motif). That would definitely hit a home run with the crowd.
By lower extension, this one's simple as to be avoidable, since it isn't really challenging your technique a whole lot, although for the sake of attracting and pleasing countless fans, this one's it: Krinkels' Madness style. Your duds on a character with a cross on their face. (Yeah, maybe not).
marsoupskin is another Newgrounds artist whose style you could emulate. His claim to fame is the "FAUX" digital comic series. That style shouldn't be impossible to pull off, although I haven't seen the pictures animated, which is why I figured someone worth his salt could try animating.
Jonathan Lam (nahtanojmal) is another good Newgrounds animator (notice a trend?). His cartoon style reminds me of Frank Montagna, or the people behind the E-Surance advertisements (remember the pink-haired covert agent?). Anyway, Jon is another one who could really use a tribute of some kind.
There are a few guys outside of Newgrounds whom you could try out, too:
Matt Groening authored The Simpsons. I was surprised you didn't try to emulate his stuff, no matter how simple.
Aaron McGruder is an American cartoonist and animator best known for "The Boondocks" and all the political shit it stirs. Being among the very few successful authors who adopt a Manga and Anime-inspired style on this side of the ocean, I suppose it could be a tricky venture to attempt. I actually thought--when I first saw the cartoon in the Adult Swim programming block--that it originated from Japan and was even more horrific (and hilarious) a satire for it.
Yoshitaka Amano is definitely a stretch. The wispy lines, vibrant colors, and total destruction of fashion inherent in his designs... well, if you want to give a big sendoff to the Final Fantasy crowd, look no further.
For more traditional, recognizable Manga style, try Tetsuya Nomura. Just try to keep the outfit your character is wearing consistent. No zippers or gaudy chains involved, all right?
I'm impressed you resisted the urge to try Jim Davis, of Garfield and U.S. Acres fame.
Well, that's it from me. If you're ambitious enough, try one. I don't expect you to pull off all of these suggestions, or even one, but if you wish to try, I'm pulling for you.