Spike is left alone after his friends have left this world and climbs a mountain at the request of Celestia
You totally thought I would say more in the long description didn't you.
check out who did the pic here
http://www.deviantart.com/art/Spike-the-Dragon-Rogue-Diamond-Outfit-371604214

spike was a dragon that had lived in ponyville for most of his life and lived day in day out. however, when twila lets him down one more time, on a countless list, spike comes to realize that there is nothing for him in ponyville. join spike as he journeys across equestria.