We don't know exactly what that is, but we think it could be an trinket of some sort (the wolf with wings thing). We also know that you can equip an accessory, whether they are one in the same has yet to be revealed. Either way, what would you like to detail you Guardian, giving it that extra bit of personality? I (a Hunter) would want something like a wolf as a trinket. As for an accessory (and if that's what it is) I'd want a single shoulder guard on my left shoulder. I've always styled my Spartans to have a larger left shoulder piece, so I think I'll try and bring that over to Destiny.