Fictitious name of someone is not to who mention. You can have a Latin origin where scitanus is the way to call something already known or known; as also come from the interjection " zut! " formerly used for the attention of a stranger. This resulted in the medieval form " Don Zut " way to name a male whose name is ignored, that affinity with Fulano, Mengano and Perengano, ended as Zutano.