Can I put this Google Gadget of Calvin and Hobbes on my website for free legally?”
Bill Watterson is famously protective of his creation. Other than books of his Calvin & Hobbes strips, he has never licensed any merchandise. He’s written about this at length in many of his books. Although he’s been offered mountains of money to license various Calvin & Hobbes merchandise, he’s never wavered on this. He simply doesn’t want his creations rendered in different forms and has never allowed any merchandising of his work. The closest I can find to a official source is the discussion of the topic on this site: http://www.nivmedia.com/calvin/merchandising.php Hope that’s helpful!