Lonesome Pony is the name of a DJ who runs a radio station along Route 52.
During Puppysmiles Journey
Lonesome Pony acted as a voice of hope and reason along Route 52, much like DJ Pon3 does across most of the Equestrian wasteland. Lonesome Pony often reports Puppysmiles exploits along Route 52, nicknaming her The Ghost of Route 52. Lonesome often states happiness about Puppysmiles actions but laments that it took a filly to do them, when the Route is populated by many, much more capable ponies.
Lonesome Pony tries to track down Puppysmiles and joins a group of friends she made on her journey, hoping to avert a prophecised disaster, made by the Sand Sweepers prophet/mystic. Lonesome accompanies Henrietta only to discover that Puppysmiles has learned of her mother's death and he assists in the battle against Creepyvoice after it takes over Puppysmiles.
Lonesome Pony returned to his post as a DJ and used his radio station to help organize a resistance movement against the Enclave along Route 52, limiting the potential damage the Enclave might have caused had they been unopposed. He also spoke with Spike over long distance as part of the interviews Spike conducted with various ponies Puppysmiles met on her journey.