Card Passer is a former high-ranking G.U.N. commander who led an unauthorized attack on Dr. Eggman, but only to be stripped of his rank by the President for acting without unauthorization and fired from his position. As a result, Passer joined the S.O.N.I.C.X. organization to get revenge on Sonic the Hedgehog for making him lose his job. (SX: #23)
Card Passer and the members of S.O.N.I.C.X. were able to capture Sonic, and voiced his and the organization's reasons against Sonic. However, Sonic mocks the group's name, believing it to be a fan club, in which Passer and the others gave heated looks on Jerome Wise, who thought up their expanded name. Unfortunately for Passer and S.O.N.I.C.X., Sonic easily managed to escape from them. (SX: #23)
Much later, Passer and S.O.N.I.C.X. concocted their next attack on Sonic by tarnishing his name by creating an army of Sonic clones; but the clones are accidentally made with different colors, leading the public into believing they are related to the original, although not the original himself. Because of that, Passer is the first to scold Dr. Kai Narasu, the creator of the clones, for his mistake, but after their leader, the Organizer shows them a news broadcast where Sonic challenges the clones to a duel, Passer's overconfidence got the best of him as he decides to see the plan to the end. However, the clones were eventually destroyed by Dr. Eggman. Passer was then tricked into destroying the final clone by Sonic after seeing the clone's shadow among the smoke, making him think that it is the real Sonic and have it shot. (SX: #37)
- Card Passers presence in the comic actually creates a continuity error between the comic and the show: his single appearance in the anime, in episode 50, was the episode in which Sonic and friends where making preparations to return to their home planet in order to prevent their planet and Earth from merging together causing time to freeze. Card Passer was arrested during the episode, with the Mobians returning home later in the same episode, rendering Sonic's meeting with Card Passer a second time impossible.
- As an explanation, Ian Flynn came up with the theory that the two planets slowly merging together was causing time to slow down, allowing for Sonic and friends to spend extra time on Earth. For the anime, this would imply that a considerable amount of time had passed between the beginning and ending of episode 50.