Arthur Dent is described as "about 30 ... tall, dark-haired, and never quite at ease with himself." He is an ordinary human being living a quiet life in a house on the outskirts of an English village. He enjoys an ordered life and a fresh cup of tea. None of this prepares him for being plucked from Earth and launched into a series of bewildering adventures while being shuttled around the galaxy. Even so, he tries to rise to the occasion and cope. On occasion, he breaks his general passivity to become a man of action. Arthur is one of two surviving members of the human race after Earth's destruction. Though insignificant compared to the vastness of the universe, his humanity and human perspective allow the audience to relate to the absurd situations in which he finds himself. And the question is: What does Arthur's survival mean to the universe?
Ford Prefect is moderately tall and good-looking in an inconspicuous way, with wiry, reddish hair. He is not human, however, and has been stranded on Earth for 15 years while posing as an out-of-work actor from Guildford. In reality, he is a researcher for The Hitchhiker's Guide to the Galaxy and, as such, has a great deal of experience as a galactic hitchhiker. Having befriended Arthur, he rescues him from Earth's demolition and acts as a kind of mentor during their space adventures. In times of danger, Ford views the situation realistically, even somewhat fatalistically, while on the lookout for a way to escape. He manages to remain upbeat even at the worst of times, and often exhibits a dry, dark sense of humor. Curious, energetic, and keen for adventure, he is a foil for Arthur, who enjoys order, predictability, and a nice cup of tea. Ford is Zaphod Beeblebrox's semi-cousin, and they grew up together. Knowing Zaphod well allows Ford to perceive that something is not right when he meets up with his semi-cousin aboard the starship Heart of Gold.
Prostetnic Vogon Jeltz
Prostetnic Vogon Jeltz is a typical inhabitant of the planet Vogsphere, with green, rubbery skin and a highly domed nose above a small, piggy forehead. He is a Vogon civil servant: bureaucratic, thick-willed, sluggish-brained, and stubborn. He also hates galactic hitchhikers. As captain of the Vogon Constructor Fleet, Prostetnic Vogon Jeltz's assignment is the demolition of Earth to make way for a hyperspatial express route. Unfortunately, Ford and Arthur choose his ship for their hitchhiking escape from Earth before its destruction. When Prostetnic Vogon Jeltz finds them aboard, he takes great pleasure in torturing them with his poetry before tossing them off his ship into outer space. Vogon poetry is well known for being the third worst poetry in the universe.
Zaphod Beeblebrox has recently become the celebrity President of the Galaxy, apparently in order to steal the new starship Heart of Gold. He is formerly from Betelgeuse Five and semi-cousin to Ford Prefect. Besides his unique physical characteristics, his qualities of mind—dash, bravado, and conceit—make him larger than life and a legend in his own mind. He even says, in fact, "If there's anything more important than my ego around, I want it caught and shot now." He attacks everything "with a mix of extraordinary genius and naïve incompetence," and things always seem to work out in his favor. Zaphod is the inventor of an alcohol-based wonder, the Pan Galactic Gargle Blaster, and runs a very lucrative secondhand ballpoint pen business. He uses the Heart of Gold to find the legendary planet Magrathea. As unlikely as it seems, he and Arthur met six months before Arthur and Ford were picked up by Zaphod's starship. At that time, he had called himself Phil and lured away a girl Arthur was making a play for at a party. Now thrown together with the Earthman, Zaphod considers Arthur a relatively useless addition to the starship's crew. By the end of the story, however, he gains a grudging respect and accepts the Earthman as one of the group.
On Earth, Trillian was known as Tricia McMillan. Since hitching a ride with Zaphod Beeblebrox to explore the galaxy, she calls herself Trillian. She is described as "slim, darkish humanoid, with long waves of black hair, a full mouth, an odd little knob of a nose and ridiculously brown eyes." Arthur adds the descriptors of beautiful, charming, and devastatingly intelligent. The latter is supported by the fact that she holds degrees in math and astrophysics. She is, however, jobless, and the idea of putting her skills to use in space is enticing. She brings along her two white mice. Throughout the story, Trillian acts as a sidekick to Zaphod. She seems to understand more about how the starship Heart of Gold works than anyone else. She is not, however, as clever at figuring out her traveling companion. She is never quite sure if Zaphod is pretending to be stupid because he's too lazy to think for himself, pretending to be stupid to hide his ignorance, or genuinely stupid. She does her best, however, to make sure he does nothing that will blow up the ship.
According to the Sirius Cybernetics Corporation, a robot is defined as "Your Plastic Pal Who's Fun to Be With." Marvin is anything but fun, although his observations about life are darkly funny. "Life," he says dolefully, "loathe it or ignore it, you can't like it." He is a prototype for a new generation of robots and computers endowed with GPP (Genuine People Personalities) features. In the attempt to make robots that expressed human emotions, however, the corporation never expected that the emotion could be despair. "Life!" laments Marvin."Don't talk to me about life." His despair seems to stem from dissatisfaction with his lot in life. He hates the starship's cheery doors that open and close with pleased self-satisfaction, having done their job well. Upon meeting Ford and Arthur, Marvin complains, "Here I am, brain the size of a planet and they ask me to take you down to the bridge. Call that job satisfaction? 'Cos I don't." Nevertheless, Marvin does his part to help the humanoids he serves survive and make it out of their adventure in one piece.
Benjy and Frankie
Back on Earth, Benjy and Frankie were two white mice who, by luck, left the planet early for a brief holiday before its demolition. They are actually hyperintelligent pandimensional members of a race who look somewhat humanoid. In the form of mice, they helped run the 10-million-year-long computer program called Earth, to learn the Ultimate Question to fit the Ultimate Answer to Life, the Universe, and Everything ("Forty-two"). Scientists by profession, celebrity seekers by nature, the two mice want to return home and turn their Earth experience into profit on chat shows and the lecture circuit. But they are still missing the question to fit the Ultimate Answer. With the hope that it is stored somewhere in the Earthman Arthur's brain, they plan to remove and dissect his organ. They are as icy in their resolve as any human laboratory scientist might be.