One of the Uratha in our pack has the first dot of the Unarmed Defense merit:
From God Machine Chronicles, p65:
Like a Book (*): ... When facing an unarmed opponent and not Dodging, increase your character's Defense by half of his Brawl (round down).
Does a werewolf using claws or teeth (in an appropriate form) count as being unarmed? Does a spirit that attacks with claws count as unarmed?