1)The hole in the middle he is coming out of could be filled in a light blue
2) You could consider adding his shirt, vest w button
3)Put the Fin on a bit of an arc.
4) Maybe make your pig the same color as porky pig
5) As far as the drawing, the ears could be more defined esp the right one (viewers left) Without a reference it hard to say, but maybe work on the snout a bit
Really cool. However I think the shading needs a bit more work and I'd take out the line leading up to the fin./ Maybe put the fin up larger at the top of the design. Really cool