As Mark Rosewater already told everyone, Garruk Relentless, as we saw on the stand-in transformation card, is a double-faced Planeswalker, and is the planeswalker with 5 loyalty abilities. No one’s quite sure what he is or what he’ll be doing in Innistrad. It’s possible he’ll be a werewolf and help the werewolves to transform and transform himself into a werewolf planeswalker, maybe giving us a green werewolf Garruk, similar to Gideon’s zero ability to make himself a 6/6 soldier? It’s all speculation at the moment.