The Golgafrinchan are a race of beings who realized that there were three types of beings on the planet of Golgafrincham. Thinkers, Workers, and the strange Middle Class.
The middle class comprised of hair dressers, lawyers, telephone steriliziers, and other such "worthless jobs."
The Thinkers built a ship and told the third class that the planet was to be consumed by a "giant space goat." So they built a ship and sent off their third class. Telling them that they would follow soon. The Third class ended up on earth, "mucking up the program to determine the ultimate question." While the rest of the classes were killed off by a raging disease contracted from public telephones. Golgafrincham soon after was consumed by a giant space goat.