'Moomin's Winter Follies' by Tove Jansson - all about the silliness of Moomins in the winter. For more Moomins in winter, check out this book.
Read here for more about the Moomins. I'm starting to repeat myself when it comes to the Moomintrolls. For the love of all that's cute and fanciful, please get some Moomin in your life!
I almost didn't feature this book, because parts of it aren't the most politically correct, but the books and the comics were written long before people might have worried about that sort of thing. There's a sort of Bugs Bunny-ish wild west language-y part where one character threatens to "blow the brains" out of another character, and well if that offends, than maybe this book is not for you.
It really is silly, whimsical fun though. Even the part where Moomintroll thinks about pushing a rival off a cliff with a tree trunk. And the part where the same character who almost goes off the cliff gets smothered in snow. (he's ok!) Also one character calls another character an ass. See, what did I tell you? Silly, whimsical fun! Did I mention this book was written a long time ago?
There are other comics! See here. I myself love the chapter books the best, but this has tons more of the adorable Moomin art, which is always fun. When it comes to Moomins, it really is best to just collect everything. Just get them ALL.