One possible version of Peter Petrelli is the version that exists in Arthur Petrelli's future.
This version of Peter again dons the vertical scar across his face which all his future counterparts share apart from the Peter Petrelli (The Outbreak Future) from the "Outbreak Future" since he is dead so we cannot know. He has become a terrorist in this timeline and is causing mayhem within his city along with other rogue evo's.
Peter is constantly being hunted by Claire Bennet (Villains future) due to her finding out that he killed thousands of people, even people she cared about. after travelling to the past Peter gets caught off guard by Clair and the Haitian, here Peter meets his end by some round fired from Claire's pistol.