X the Phantom Fed, or as he is sometimes known, Secret Agent X, is the perfect covert agent, so adapt at taking the identities of other people that he seems not to have one of his own anymore.
Who he is, where he came from are any information about his “real” self has been left behind, with no one, having seen his real face in years.
X moves from mission to mission, taking the guise of another person and living as that person until the mission is completed and he moves on to his next assignment.
The only person who may know who he is, is his boss in Washington who is known only as K-9.
X the Phantom Fed was based on the Ace Magazines Pulp, Secret Agent X, which ran for 41 issue between February 1934 and March of 1939.
The stories used for X the Phantom Fed were taken from the first half dozen Secret Agent X stories and adapted for the comics.
While we have not heard from the Phantom Fed sence 1940, Secret Agent X had returned in The Battle for L.A. from Moonstone