I made this adorable little fella using 2 strand crochet cotton (14wraps/cm) and 1.5mm hook. The finished platypus is 3.8cm tall, and super cute! I think he will probably end up attached to my mobile phone.
The awesome free pattern is available here on Craftster, courtesy of Beavisfreak. (You may need to register on Craftster to view the pattern, but that only takes a minute ). The platypus in the photo in her pattern is considerably larger than my little guy. I did not have any trouble following the pattern exactly to make this tiny, scaled down version though.