looks better with DB's palette. The outline on the white stomach is too dark imo. highlight on the head doesn't conform to the light source. there's banding where the stomach meets the wing.

other than that no major crits, it's successful for what it is, which is a generic cartoon-y penguin. I think you could make the design more interesting by making him less generic (in terms of character design and species) give him a bit of character. a winter hat (we call 'em toboggans in the South), a scarf, some sort of hairstyle feathers up top, etc.

You could also reference actual penguins. he'd have more interesting features/ colors if he were a macaroni penguin, or an emperor penguin, for example. you could also match the anatomy a bit more. I don't mean it needs to be realistic, just that your abstractions of the form would be more convincing if they were based on the actual anatomy, and not just circles.