Submission for Equestria Daily's Fluttershy Day.
Based on the seapony designs from My Little Pony: Set Your Sail, the G5 comic miniseries. Each one seems to be based partially on some sort of sea creature; initially my idea was an angelfish or a sea angel, until I remembered that butterflyfish existed. (The wings were added after I finished everything else on her.)
Angel is a sea angel, but he's not too thrilled about it! (and he's pink.)
(It was also going to have a proper undersea background, but then I got lazy.)