I don't know of anyone who doesn't love a platypus, although the critters can be dangerous. The have poison spikes on their back legs that can do you up a treat if they stick you with one, although if you have one raised from infancy, it seems that it's not inclined to spike you, because I've seen people on TV handle platypuses without harm.
This book is part of a big series (Blastoff! Readers: Animal Safari) on different animals, but this same author and judged from this one, it looks like this is a fun and educational series. despite being quite short, it's full of informative text (although not too much!) and a bunch of photos of cute-looking platypuses. I recommend it for any kid who is interested in learning about a specific animal. Whether you'd want to get the whole series is another issue! That would be some investment.