Zaphod Beeblebrox is from a planet in the vicinity of Betelgeuse, and is a "semi-half-cousin" of Ford Prefect, with whom he "shares three of the same mothers". Because of "an accident with a contraceptive and a time machine", his direct ancestors from his father are also his direct descendants.

Zaphod is the inventor of the Pan-Galactic Gargle Blaster, a cocktail based on Janx Spirit. The series states that the effect of one "is like having your brain smashed out by a slice of lemon wrapped round a large gold brick." In the television series, two Gargle Blaster drinkers collapse in open-eyed unconsciousness after drinking while the spilled drink burns a hole in the floor; in the film, after the Guide is done explaining what the Pan-Galactic Gargle Blaster is and its effects, Ford and Zaphod yell in pain. The Hitchhiker's Guide to the Galaxy gives the recipe as follows:

"Take the juice from one bottle of that Ol' Janx Spirit.
Pour into it one measure of water from the seas of Santraginus V
Allow three cubes of Arcturan Mega-gin to melt into the mixture (it must be properly iced or the benzene is lost).
Allow four litres of Fallian marsh gas to bubble through it (in memory of all those happy Hikers who have died of pleasure in the Marshes of Fallia).
Over the back of a silver spoon float a measure of Qualactin Hypermint extract, redolent of all the heady odours of the dark Qualactin Zones.
Drop in the tooth of an Algolian Suntiger. Watch it dissolve, spreading the fires of the Algolian suns deep into the heart of the drink.
Sprinkle Zamphour.
Add an olive.
Drink...but very carefully."

The Guide also implies that there are multiple voluntary organisations available to rehabilitate those who would try the Pan-Galactic Gargle Blaster. Real versions of the drink have been made available at some stage shows of The Hitchhiker's Guide to the Galaxy, as well as bars such as Zaphod Beeblebrox in Ottawa, Ontario, Canada. Recipes for these "Earth versions" can be found at Wikibooks.[4] In an interview,[5] Douglas Adams stated that there are a number of environmental and weapons treaties, as well as laws of physics, which prevent the Pan Galactic Gargle Blaster from being mixed on Earth.