Joe Bloggs

"Joe Bloggs" and "Fred Bloggs" are placeholder names used primarily in the United Kingdom to represent the average man on the street. It is used by students, on standardized test preparation courses, to represent the average test-taker. Many countries, such as the United States, Germany or South Africa, use their own unique placeholder names, some even used tongue in cheek. Sometimes the name will be useful as a quick alternative, or stalling mechanism especially when used in conjunction with "What's'isname?" and "'im down the street", when a forgotten name sits on the tip of the tongue.
Examples.
In The Princeton Review standardized test preparation courses, "Joe Bloggs" represents the average test-taker, and students are trained to identify the "Joe Bloggs answer", or the choice which seems right but may be misleading on harder questions.
"Joe Bloggs" was a brand name for a clothing range, especially baggy jeans, which was closely associated with the Madchester scene of the 1990s.
History.
The name "Bloggs" is believed to have been derived from the East Anglian region of Britain, Norfolk or Suffolk, deriving from "bloc", a bloke. In the UK, a "bloke" represents the average man on the street.
Similar cases.
In the United Kingdom and United States, John has historically been one of the most common male first names, and Smith is the most common surname in each, so "John Smith" is a recurrent pseudonym and placeholder name in those countries (especially in legal contexts).
Other placeholders, often used in advertising store cards and credit cards, are Mr/Mrs A Smith or A. N. Other.