The Gray Ghost, played by Simon Trent, was a fictional television hero from Bruce Wayne's childhood.
Before his parents' deaths, Bruce often watched The Gray Ghost on television with his father. The dynamic costumed vigilante helped shape the vigilante persona Bruce Wayne adopted later in his life, the cape and cowl of Batman.
Decades later, however, Simon Trent was little more than a washed up, typecast actor. Unable to pay his rent, he slowly sold his Gray Ghost memorabilia to cover the bills. Frustrated with his life, he regretted his decision to ever play The Gray Ghost, destroying the few pieces of the collection he had left. However, fate, chance or perhaps just very careful planning brought Batman into contact with Trent. Though he was investigating a bombing spree similar to one depicted in The Gray Ghost, Batman revealed to Trent the importance and influence the character had on him in his early years. Trent, himself, would, upon seeing the Batman's personal collection of Gray Ghost merchandise, say that playing the Gray Ghost wasn't all for nothing, glad that what he had done had a positive influence. Trent redeemed himself, donning The Gray Ghost persona once more, and aided Batman in unraveling the mystery of the Mad Bomber. The Bomber turned out to be a toy collector who used Trent's memorabilia to re-enact an episode of The Gray Ghost.
Shortly thereafter, a major home video release of the long lost TV series was made from Trent's personal film collection, likely making him a wealthy man. During a public video signing (in costume), Bruce Wayne acquired Trent's autograph and subtly revealed to his hero his own secret identity, which pleased Trent to no end.
- The Gray Ghost being an inspiration to Batman is an acknowledgment to all the pulp/radio heroes like The Shadow and Green Hornet that predate the creation of the character in 1939.
- The Gray Ghost is voiced by late Adam West, the actor who played Batman in the television series and associated movie. Bruce Timm and Paul Dini have stated that they would not have made the episode in which he appears if West had turned down the part, as they feared he would be offended by an animated parody of the typecasting he reportedly suffered in his later career. West, however, was happy to voice the character.
- Gray Ghost posters make several appearances in the background of the various shows.
- Over time, Bruce Wayne filled the Batcave with several pieces of memorabilia from his life. One piece is the outfit worn by The Gray Ghost. It's unknown if the outfit is the original or a replica Bruce acquired.
- The Gray Ghost received a nod in the Batman Beyond episode "Black Out". During the episode's climax, the shapeshifting Inque battles both Batmen (Terry McGinnis and the aged Bruce Wayne) in the Batcave. To conceal his identity, Bruce, ever the quick thinker, dons the hat and goggles of his old hero.
- The character received a special nod in the Justice League Unlimited episode "Epilogue". As the Phantasm prepared to eliminate Warren and Mary McGinnis (in front of young Terry's eyes), the family is seen exiting a production of "The Gray Ghost Strikes Back!" However, the title is misspelled using "Grey" instead of "Gray", a common error for the character beyond his original debuting episode.
- West voiced a similar character on Disney's Kim Possible, a retired crime-fighter called "The Fearless Ferret." His costume is adopted by Kim's sidekick, Ron Stoppable, who is voiced by Will Friedle, the actor who voiced Terry McGinnis.
- In the video game Batman: Arkham Knight, there is a "The Ghost in Grey" poster in Panessa studios, a reference to the character.