Zeppelin is a mythical character and a pedestrian in Grand Theft Auto: Vice City. He’s named after the German Count Ferdinand von Zeppelin, pioneer of a type of airship named Zeppelin while some have argued that his name is derived from the British rock band Led Zeppelin. Zeppelin was also featured in the Vice City Manual.
Zeppelin is veteran member of the Biker Gang at Greasy Chopper and loyal ally to the leader of the Biker Gang, Big Mitch Baker. He works with Cougar, another member of the gang. Cougar and Zeppelin play a major role during the mission, Alloy Wheels of Steel, when they race with Tommy Vercetti on the orders of Big Mitch Baker, eventually losing to him, paving Tommy’s way into an inter-gang affiliation. In the myth hunting world, Zeppelin is known for his t-shirt, bearing an alien artwork. The artwork is of an alien head, commonly used as a logo to represent alien entities in real life. This has lead players to believe that Zeppelin maybe either an alien enthusiast or an alien himself. The myth was later busted with the help of Zeppelin’s artwork from GTA Vice City Stories, showing that the alien head is actually a metal skull that lacked detail and texture in the game, giving the impression of an alien head.
Zeppelin could also be a reference to the English band called Led Zeppelin, famous during the '70s. This could be hinting towards a dark Satanic reference.
According to this site, a Christian right forefather Paul Crouch revealed in the early '80s, that if the one plays certain parts of Stairway to Heaven on rewind, close their eyes, and listens real hard, the high-pitched noises sound similar to "Here's to my sweet Satan" and "He will give those with him 666." The only problem is that the weird squeaky playback sounds vaguely resemble any number of words in the English language, and the Satanic "message" is more a result of Crouch's paranoia than any master plan on Led Zeppelin's part.