Re: Toucans - what's missing?
I'm certainly no expert - I've been at this for such a short time. So take my advice with a grain of salt. But here's what I see...
Did you use tube black, or mix your own? Using your own mix also helps prevent that flatness. I might also add a bit of complementary color wash to the parts of the beak so it's not so clean.
I'd also probably add some dark purple to the eye...not the whole thing...just a small bit to give it some depth.
Do you have white gouache? I'd add a tiny dot to his eye to show a bit of reflected light.