My spirit animal is a fox and foxes are my favourite animal, so I'm going to say fox. As a lycanthrope though probably something like a werevulture, but maybe an eagle or a raven. If any of you have ever seen the film Howl's Moving Castle, that's the kidna thing I'm thinking of. If not just a werewolf of course :)
Well, seeing as my favourite animal is a robin, I'd have to say a robin. European Robin, of course, as they are significantly larger and more aggressive than their American counterparts. Great for a surprise attack, as nobody would expect a robin to attack somebody, and for fantastic reconnaissance.