Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-96.238.1.154-20130804085459/@comment-88.90.149.175-20130813004629

Peter could transform into the "beast-werewolf on steroids" because he was driven by anger and wanted revenge after Kate and her "b****es" broke the code by burning down their family house, with innocent people inside. He killed "only the responsible ones" as he said himself, and in order for that to happen he went full beast mode. All that anger and hatred he had against them, made his wolf form like that to create a "nightmarish" beast you would be terrified to see bacause he was furious. Also, as stated earlier, "sometimes the shape you take reflects the person you are" and after beeing in a coma for 6 years with his human side pretty much burned out on the inside I suppose his wolf side had taken more control.