Zaphod Beeblebrox

Zaphod Beeblebrox is a protagonist villain and one of the two triagonists of the Hitchhiker's Guide to the Galaxy franchise. He is the semi cousin of Ford Prefect, the former president of the galaxy and an alien born on the fifth planet of Betelgeuse. Despite being one of the main protagonists of the series Zaphod himself as an incredibly despicable, narcissistic and spontaneous character.

In the radio show and TV series he was voiced/portrayed by Mark-Wing Davey while being portrayed by Sam Rockwell in the 2005 Disney/Touchstone film adaptation who also portrayed Justin Hammer in Iron Man 2,

The Hitchhiker's Guide to the Galaxy
Zaphod was first mentioned by Arthur Dent when the latter was explaining the story of how he blew it with a girl named Tricia MacMillan due to how she was won over and charmed by a man named "Phil" and how he never saw her again. Zaphod himself appears soon after when he and Tricia (now known as Trillian) steal the spaceship the Heart of Gold when Zaphod was supposed to launch it as part of his presidential duties and are now on the run from the intergalactic authorities. Zaphod is seeking to find the answer to the Ultimate Question and is taking Trillian and the ship's robot Marvin the Paranoid Android with him to the planet Magrathea, however the two wind up picking up Arthur Dent and Ford Prefect by accident and now have two more passengers accompanying them on their journey.

Once arriving at Magrathea Zaphod purposefully separates the group, leaving Arthur and Marvin stranded outside while he Ford and Trillian explore the planet, they are soon encountered by two white mice Trillian formerly had as pets known as Frankie & Benjy who take them to have a feast. Soon following this Arthur regroups with the crew and the mice announce their true intentions to remove Arthur's brain. Following this, the group run away but are encountered by the police. Ford and Zaphod say their goodbyes to each other and begin singing a famous Betelgeuse death anthem anticipating death. Luckily however they are rescued when they are transported through time to the restaurant at the end of the universe.

The Restaurant at the End of the Universe
In this story Zaphod has a small role. He appears with the main crew briefly before being separated and forced to enter the total perspective vortex which he surprisingly winds up being the first survivor of. Following this he escapes by using the shrunken heart of gold inside his pocket and is reunited with Trillian. He is also reunited with Ford, Arthur and Marvin towards the end of the book.

Life, The Universe and Everything
Coming Soon

So Long and Thanks for all the fish
Coming Soon

Mostly Harmless
While not featuring in the novel at all Zaphod is briefly mentioned on a few occasions and was supposedly seconds away from showing up before the ending of the book.

And Another Thing
Coming Soon

Radio Show
Two key differences appear in the radio show as shown through how the events which occur to him the second book are what canonically happened to him whereas the radio show's second series was merely a drunken hallucination.

The further difference is shown in the end of the quintessential phase. While in fifth book Zaphod doesn't appear at all and all of the other characters (bar Marvin who already died at the end of the fourth book) die, this is retconned in the radio show as Zaphod appears to save the crew just in the nick of time.

Film
In the film Zaphod's actions are vaguely similar to the novel however his character is drastically changed as a result of Humma Kavula removing his second head. Following this Zaphod's personality flip flops from being ridiculously stupid and then becoming wildly depressed.

In this adaptation he presumably returns to being president and breaks up with Trillian much earlier than in other adaptations.

Personality
Zaphod appears to have narcissistic traits and is characterized by his deceptive stupidity and spontaneously mercurial interests. Zaphod is also incredibly excitable and hedonistic as well as uncaring yet charismatic, he's almost always happy or at least content and enjoys fame and attention.

In the movie adaptation Zaphod's stupidity is severely exaggerated and he is shown to have incredibly violent tendencies as shown by his constant physical abuse to Arthur Dent. Once his second head is removed in the movie however he appears to be much more stupid than his book and radio counterparts and becomes severely depressed, likely meaning that in this adaptation he has a split personality within each head, a trait he lacked in the books.

Appearance
Zaphod is often characterised by his two heads and eccentric fashion sense. While in the TV Show he has a left and right head just like in the novels and radio series in the movie his head is hidden underneath his neck. Zaphod's dress sense also appears to be more alien in the books and TV Series as opposed to his Rockstar-ish dress sense in the film.

Trivia

 * In every visual adaptation Zaphod's second head is done in an entirely different way. In the TV series a latex animatronic was used, in the film a rubber mask and filming technique was used over Sam Rockwell's normal face and in stage adaptations the Pantomime horse technique was used which involved two actors in one costume giving the illusion of two heads and three arms.