"Bob" was also the name of the generic human civilian in Bungie Software's 1995 first-person shooter Marathon. As the story goes, the U.E.S.C. Marathon's voyage from Mars to Tau Ceti took long enough for at least one new generation of colonists to be born; some colonists took to naming their sons Bob, short for Born On Board. It caught on quite well, and now Marathon players happily refer to every civilian aboard the ship as Bob - affectionately or, as is somewhat more common, not so affectionately.
Bobs first appeared in Marathon 1 completely unarmed. They just ran around and got in the way, often suffering unspeakably at the player's hands (for no particular reason). In Marathon 2 and Infinity, however, they worked up the courage to grab some guns and fight alongside you, despite the countless deaths you caused them. Pretty forgiving of them, if you ask me. Of course, if you massacre enough of them within plain view, they'll start to get a bit angry.
The Bob is also known for his random chatter: such timeless phrases as "Frogblast the vent core!" "They're everywhere!" and "I'm comin' outta the booth!"