Doctor of an ambiguous doctorate

"Doctor Blowhole. But... not that kind of doctor!"

Regradless of what he's a doctor of, what would be a POM fanfic without this dolphin lurking nearby?

I've made this piece a good chunk of time ago. Just recently I found it again and did a bit more of work on it. It doesn't look as good as it could but for a half-older piece, I think it's not terrible, either. Only the face... He should look like rolling his eye but the grin is too wide for a frown. And the teeth... uncanny just enough for Halloween, had I been home yesterday already xD

What do you think? Is there something about the pic that I could improve? I'll be glad for comments

Reference: An image of Dr. Blowhole in (similar to) this pose from Google (I may add a link if I find it again)
Disclaimer: An older (and terrible) version of this piece can be found on my sister's Sketch account. I used to post my art through it (sometimes even in her name) before heading to DA. 
Disclaimer 2: The character isn't mine and thus belongs to his respective owners

The (former) quote: From this chapter fav.me/dbnojjz