Jeff Z. is a defunct pseudonym created by Snopes.com co-founder David "Snopes" Mikkelson.
Regrettably, this pseudonym is tied to a considerable number of retracted stories due to plagiarism and poor attribution.
The fictitious bio to accompany this byline was as follows:
Jeff Zarronandia is the pseudonym of J. Eff Zarronandia, an American author and journalist who won the Pulitzer Prize for numismatics in 2006 and was one of four finalists for the prize in 2008. He was also the winner of the Distinguished Conflagration Award of the American Society of Muleskinners for 2005.