If I had to do it over again (which I probably will...), I think I would have definitely done a black outline around the eyes and made the eyebrows two rows of black instead of one. I might also have two rows of black outline for the beak...not sure about that. Maybe make the ends of the bill a bit more rounded?
Also, keep in mind, the black yarn is thinner than all the other yarns. The orange is slightly thinner than the turquoise and white. This was just a prototype using yarn I already had. When I do it again, I'll buy yarn that is all the same. I guess what I'm trying to say, is I think I can do much better. This one was for a friend of my daughter, so she only got to wear this for the photo.
I decided to knit the pattern part flat. I C/O 72 and did a K1, P1 ribbing for three rows. I did one row of turquoise before starting the pattern, then just used a stranded/intarsia combo method. Once I got past the eyebrows, I switched to circulars till decreasing (I decreased at 6 points around) then DPNs as it became smaller. I tied it off at the top, wove in all the ends, then stitched it up in the back. Not sure what the stitch is called, but you can't tell it's been stitched up unless you tug at it.
Before I try this again, I'm going to do a version with just one color where the pattern is outlined by purl stitches on a knit background (or vise - versa).
I won't be selling these, of course since I'm not licensed to use Perry the Platypus. If they tell me cease and desist from making them, even for free, I might get a lawyer and tell them I'll cease and desist when they put a Perry Hat out there that is made like this (or better) --and not like this:
You see how the bill and eyes are just embroidered on top? That is just cheating!