It looks like the internet forum intellectuals were wrong on this one. The green/red werewolf isn't legendary after all:
Now that all the 4cc werewolf slots have been revealed, I'm kind of liking their design. Like I said in my impressions for Afflicted Deserter, the 4cc slot is kind of packed, but they all kind of have a role to play. Huntmaster is now the most powerful, Instigator Gang has a place in token based decks, Mondronen Shaman is a potential build around, and Afflicted Deserter is a potential sideboard card. But let's get back to the card...
The value you'll get from this card is what sets it apart from all the others. The 2/2 and 4/4 bodies aren't that impressive, but every pair of transformations is a potential drain life for 2 and creature swing of +1/-1 in your favor. This is an obvious bomb in limited and you'd be crazy to no first pick it. The fact that it's legendary is interesting, but what I find more interesting is that Everwolf effectively shuts this card down and if Everwolf is in play under your control... you might as well be playing Tormented Pariah.
I foresee two different werewolf decks popping up and the split begins and ends with Huntmaster of the Fells. You're going to have the decks that run Huntmaster and the others that run Everwolf. They don't play nice together and they're both very powerful, but I don't see any reason why you should run both at the same time. It'll be interesting to see which one wins out.
(On the other hand, I could be completely wrong and there could just be werewolf decks that just assume Everwolf won't last forever. Players might be totally happen with +1/+1 given by Everwolf to the Huntmaster until the Everwolf dies.)