The Hitchhiker's Guide to the Galaxy is a comedy science fiction series created by Douglas Adams.
Originally a radio comedy broadcast on BBC Radio 4 in 1978, later it was adapted to other formats, and over several years it gradually became an international multi-media phenomenon. Adaptations have included stage shows, a "trilogy" of five books published between 1979 and 1992, a sixth novel penned by Eoin Colfer in 2009, a 1981 TV series, a 1984 computer game, and three series of three-part comic book adaptations of the first three novels published by DC Comics between 1993 and 1996. There were also two series of towels, produced by Beer-Davies, that are considered by some fans to be an "official version" of The Hitchhiker's Guide to the Galaxy, as they include text from the first novel.
A Hollywood-funded film version, produced and filmed in the UK, was released in April 2005, and radio adaptations of the third, fourth, and fifth novels were broadcast from 2004 to 2005. Adams did many of these adaptations, including the novels, the TV series, the computer game, and the earliest drafts of the Hollywood film’s screenplay, and some of the stage shows introduced new material written by Adams.
Info from Wikipedia
Such a vast and varied universe as that of the Hitchhiker's Guide is, of course, home to more characters than you could count. Some are humans, some are Betelgeusians, some are Vogon, and some are small furry creatures from Alpha Centauri. The only thing they all have in common is that they are original, interesting and entertaining.
This fanlisting spans a love for them all, but some are perhaps more loved than others. Here are our main heroes:
Arthur Philip Dent is the hapless human who found himself thrown upon wild adventures around the Universe. With Ford Prefect, his friend of several years, Dent barely escaped the Earth's destruction as it was demolished to make way for a hyperspace bypass. Arthur spent the following several years, still wearing his dressing gown, helplessly launched from crisis to crisis while trying to straighten out his lifestyle.
He is a "semi-cousin" of Ford Prefect, with whom he "shares three of the same mothers". Due to "an accident with a contraceptive and a time machine", his direct ancestors from his father are also his direct descendants. Zaphod has two heads, three arms and is "clever, imaginative, irresponsible, untrustworthy, extrovert, nothing you couldn't have guessed". He was also briefly President of the Galaxy.
Ford Prefect, also known as Ix, is a Betelgeusean friend of Arthur Dent's and a roving reporter for the interstellar traveling almanac The Hitchhiker's Guide to the Galaxy. Ford was responsible for the entry on Earth, which he visited by way of a Teaser and ended up stranded on for fifteen years. He was also later upset to learn that his written masterpiece had been compressed to the two words: "Mostly Harmless."
Tricia Marie McMillan, also known as Trillian Astra, is a human astrophysicist and mathematician whom Arthur Dent completely failed to chat up at a party at a flat in Islington. Among her many accomplishments are saving the universe from the Krikketers, and becoming a Sub-Etha Radio reporter under the name Trillian Astra.
Marvin, also known as Marvin the Paranoid Android, is a robot manufactured by the Sirius Cybernetics Corporation. He is equipped with "Genuine People Personalities" technology which is designed to make him more like a person. Which means he is so depressed that, when he gets bored and talks to other computers, they usually commit suicide and die. Marvin's brain is the size of a planet (because of this, he is eternally bored because nothing takes up his entire mind), enabling him to calculate the probability of just about anything.